Duchenne Muscular Dystrophy (DMD)
| What is Duchenne muscular dystrophy? |
| It is one of more than 20 types of muscular dystrophy. All the muscular dystrophies are caused by faults in genes (the units of inheritance that parents pass on to their children) and they cause progressive muscle weakness because muscle cells break down and are gradually lost. The Duchenne type affects only boys (with extremely rare exceptions) and a problem in this gene is known to result in a defect in a single important protein in muscle fibres called dystrophin. It is named after Dr Duchenne de Boulogne who worked in Paris in the mid-19th century who was one of the first people to study the muscular dystrophies. |
| How serious is it? |
| This is a very serious condition. Most affected boys develop the first signs of difficulty in walking at the age of 1 to 3 years and are usually unable to run or jump like their peers, they often struggle to climb stairs and need to use a banister for support. Rising from the floor can also prove difficult.As the condition progresses boys with DMD are unable to walk as far or as fast as other children and may occasionally fall down. Some boys also have learning and or behavioural difficulties, which may begin to manifest at this stage. By about 8 to 11 years (rarely earlier or a little later) boys become unable to walk and by their late teens or twenties the condition is severe enough to shorten life expectancy. There are however many forms of management which are now available, which have changed the outlook and which we believe in most cases can help with the complications of the condition |
| How common is it? |
| About 100 boys with Duchenne muscular dystrophy are born in the United Kingdom each year. There are about 1500 known boys with the disorder living in the UK at any one time. For the general population the risk of having an affected child is about 1 in every 3500 male births. |
| Is there any treatment? |
| Unfortunately no cure has yet been discovered. We do have ways to manage the condition, which help with its complications. These have had a very important impact on the quality and length of life that can be expected with this condition. A great deal can be done to help limit the effects of the muscular dystrophy and this includes treatments which are now definitely known to help some of the problems which may be life threatening, but no treatment is known which affects the actual loss of muscle cells. Intensive research to find a cure is carrying on in many centres around the world. You can find updates on progress in this area in the Muscular Dystrophy Campaign magazine Target MD and on the website. |
| How is Duchenne muscular dystrophy diagnosed? |
| Reliable tests are available once somebody has recognised that a child’s problems might be due to this relatively rare condition. All affected boys have very abnormally high levels of an enzyme called creatine kinase in their blood. Most hospital laboratories can do this test. But there are other even rarer causes of a positive creatine test, so for a specific diagnosis in families with no previous affected member other tests are needed. These may involve genetic testing (looking for the actual fault in the dystrophin gene) and a muscle biopsy which can be studied to look at the dystrophin protein. |
| Can we be sure there is no mistake in the diagnosis? |
| With the most reliable genetic and protein tests, the diagnosis is very clear indeed. There are only two conditions, which are at all likely to cause any confusion in diagnosis to a doctor experienced in Duchenne dystrophy - and both of these are other types of muscular dystrophy.Autosomal recessive types are about 20 times rarer than the Duchenne type in boys and can be somewhat similar, but the specialised tests can pick out the differences. The Becker type of muscular dystrophy is a milder variant of dystrophin deficiency but there may be some overlap in severity with the Duchenne type. It may be difficult in very young children to gauge severity at first but in the great majority of cases the position is clear. Protein and genetic tests can make this distinction clearer as well. |
| How is it inherited? |
| Duchenne muscular dystrophy is caused by an X-linked gene (that is, the gene is on the X chromosome; girls have two of these and boys only one). This means that only boys are affected but that their mothers may be carriers. Actually in almost half of all affected boys nowadays it turns out that the faulty gene has arisen by a change in the gene or ‘mutation’ in the boy himself and no other member of the family carries it. But this may be difficult to prove and can be decided only after careful and expert assessment of the family.In just over half of all cases the mother carries the gene but is usually not herself affected by it. Such women are known as ‘carriers’. Each subsequent son of a carrier has a 50:50 chance of being affected and each daughter has a 50:50 chance of being a carrier herself. A small number of female carriers of the gene have a mild degree of muscle weakness themselves and are then known as ‘manifesting carriers’. One of the most important things that needs to be done soon after the diagnosis of a boy with Duchenne muscular dystrophy is to seek genetic advice and appropriate tests for those members of the family who are at risk of being carriers. |
| How can we be sure that no other boy in the family has it? |
| If a boy of any age has a normal creatine kinase blood test you can be sure that he is not affected and will never develop the condition. |
| Can any carriers in the family be identified? |
| This may be less easy but geneticists can identify from the family tree which women are at risk of being carriers. A combination of creatine kinase and DNA blood tests allows the great majority of such women to be either identified as carriers or given a strong reassurance that their risk is very low. Specialised genetic advice is now available to all families. |
| Can DMD be diagnosed before birth? |
| Once a child with DMD has been born in a family, it is often possible to offer prenatal diagnosis in future pregnancies, either for the mother or for other women who are found to be at risk of being carriers. This is normally possible when DNA studies give precise information that allows the status of the foetus to be identified. This is achieved by studying the foetus's own DNA in a chorion villus biopsy. This test is performed on a tiny piece of the developing placenta usually at about the 11th-12th week of pregnancy.Further information is available in the Muscular Dystrophy Campaign factsheet Carrier detection tests and pre-natal diagnosis. |
| What medical help will he need now? |
| Very little in the early days after diagnosis. Active exercise is important but not necessarily with medical supervision though you may find it helpful to be in touch with a physiotherapist to keep an eye on things. The most important way in which a doctor can help at this stage is to help you, as parents, to learn as much as you can about Duchenne muscular dystrophy and to provide or arrange genetic advice. It should also be possible at this stage to set up an arrangement for long term follow up for continuing discussion and help. |
| What medical help will he need later? |
| Regular supervision from a clinic used to dealing with this condition will become increasingly important as the years go by. Knowing the kind of problems that can develop means that much can be done to prevent them or manage them appropriately. In the early stages, your son will be monitored carefully for signs of increasing problems with his mobility, and in particular for the development of shortening of his muscles (contractures). Physiotherapy plays an important role in helping here.As getting about becomes more difficult, extra options to help will be discussed and a plan of action decided later on, attention will be paid to management of any spinal curvature and surveillance of heart and breathing muscles. Picking up problems in any of these areas means that they can be managed properly, reducing the long-term effects. Management of heart and breathing problem has improved dramatically over the last few years and this improvement is likely to continue. |
| What can we do to help our son? |
| Being a parent is a challenge even without having a child with DMD. This news will have made you revaluate some of the hopes and expectations you had for your son. The new challenge is to move forward in the light of this information, to continue to grow as a family and value each member and ensure that he or she has an equal share of family time.Sometimes unaffected brothers and sisters miss out on the attention and affection they need because their parents are preoccupied or sad. Time devoted to them and also, to each other will make your family life a more secure and stimulating base for your son. There will not be time for everything, and it is important to recognise that and not feel guilty, but recognising everyone’s needs - including your own - is very important for you all. You may well feel very alone. Everyone’s experience is different, but in time you may find it helpful to speak to another family who have had a similar diagnosis. Your consultant or family care officer should be able to help with this. There is no doubt that news like this changes a family in very fundamental ways. You are going to have to become an expert in this new and unwelcome subject to make sure you have the confidence to foresee and prevent problems through the years. However bad it seems to start with though, families do find a way to live with DMD. Your son will develop and mature and it is important that he is encouraged to achieve all the independence he possibly can. |
| What should I tell my children? |
| This is a very difficult question and one which people often worry about. As time goes by, your son, and other children if you have them, will inevitably ask questions, which you need to be prepared to answer openly and honestly as they come up. Knowing that they can ask you questions, which will be answered truthfully, will enhance your relationship. That is not to say that you need to tell them ‘everything’ at the first opportunity. Listen to what your children are asking and answer exactly that. You may find it helpful to rehearse how you will say things - people often say that this helps and the reality is then not nearly as bad as they had feared. It is also true that often your child will know more than you think. Allowing the opportunity to talk openly is very brave. It can be a lot more satisfactory in the long run than keeping up a silence wherein everyone is trying to protect each other. It is important to reassure your other children that they are not going to develop the same problem - this can sometimes be a hidden worry and that is nobody's fault. |
| What plans will we have to make for the future? |
| The previous paragraphs may give you some ideas about planning to help your son. One practical problem that needs to be planned for in advance is how he is going to get about in your house and remain as independent as possible when he can no longer climb stairs or when he uses a wheelchair. Will he be able to go without help to the toilet or his bedroom? Will he be able to use the bath etc? Solutions can be found to these problems but special equipment may be needed and sometimes the family home needs adaptations or even an extension.The ideal house for a person in a wheelchair is sometimes a bungalow and you should consider whether you might try to find one, but for other people different solutions may be better. Local authority grants, building permission and the building work itself can all take an unbelievably long time to arrange and it can be a struggle to get what you want. It is vital to start thinking about these decisions in advance. It is also crucial to seek skilled advice before making an expensive decision about your home. The Muscular Dystrophy Campaigns Adaptations Manual, local social services and local Occupational Therapy (OT) services and perhaps your local Family Care Officers, may be able to help you get this advice. |
| What about school? |
| Most children with muscular dystrophy cope pretty well in their local infant’s school and in their first few years at junior school. Talk to your school and give them as much information as you can. Your local clinic should be able to help you keep the school fully informed. If walking becomes too precarious or access to classrooms, toilets or dining room becomes too difficult some schools will make special arrangements or even structural alterations. Local authority transport to and from school can be arranged if necessary as can help in the classroom. If the school is too unsuitable an alternative mainstream school in the district or a special school will provide the answer.Alternatively when he leaves school your son will naturally find it difficult to do a job requiring any muscle strength, and his leisure activities will be restricted in the same way. From the earliest days at school his education is therefore going to be doubly important so that his talents, whether as an artist, organiser, writer or whatever can be fully developed. Computers offer a real route to help children with DMD develop their talent to the best of their abilities. Higher or further education often offers good opportunities for school leavers. Some boys with Duchenne muscular dystrophy are found also to have learning difficulties. This problem is rarely severe and when it does occur, unlike the muscle weakness, it never becomes worse as time goes by. In those boys who have the problem, language and communication skills are often the main difficulty. Manual skills, design sense and imaginativeness are often excellent which is perhaps why many young men with Duchenne muscular dystrophy become very good artists and model makers. As parents you can work with the school to discover and develop your son’s best talents as well as helping him to learn to cope with tasks he finds difficult. |
| ---------------------------------- |
| Support Group |
| The Duchenne Family Support Group is run by parents who have children with Duchenne muscular dystrophy and offers informal support and friendship. For further details please contact: |
| 78 York Street |
| London |
| W1H 1DP |
| Tel: 0870 241 1857 |
| Helpline: 0870 606 1604 (restricted hours) |
| Web: www.dfsg.org.uk |
| Email: info@dfsg.org.uk |
| Action Duchenne campaigns for better care for people with DMD: |
| Action Duchenne |
| Epicentre |
| 41 West Street |
| London |
| E11 4LJ |
| Tel: 020 8556 9955 |
| Web: www.actionduchenne.org |
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Becker Muscular Dystrophy (BMD)
| What is Becker muscular dystrophy? |
| The muscular dystrophies (MD) are a group of genetic disorders, which cause muscle weakness. The Becker type was first recognised in 1956 and is now known to be a much milder variant of the better known Duchenne type of MD. Becker MD is generally slowly progressive and affects only males. |
| What causes it? |
| A fault in a particular gene (dystrophin) carried on the X chromosome leads to the formation of a faulty protein in muscle fibres. This protein, also called dystrophin, is absent or severely abnormal in Duchenne MD. In Becker MD a milder fault makes the dystrophin molecule smaller (or occasionally larger) or less abundant than normal. When dystrophin is abnormal the muscle fibres gradually break down and the muscles slowly become weaker. These dystrophin abnormalities in muscle provide a very good test for the diagnosis of Becker MD. |
| What are the symptoms? |
| The average age at diagnosis in BMD is 11 years but the range is very wide - sometimes the diagnosis may be made in early childhood or well into adult life. Symptoms usually begin very mildly in childhood; often cramps on exercise are the only problem at first but a few affected boys are late in learning to walk. Most people with BMD are not very athletic in childhood, and many struggle with school sport. Later, in the teens or twenties, muscle weakness becomes more evident causing difficulty in rapid walking, running and climbing stairs. Later still it may be difficult to lift heavy objects above waist level. Men with typical Becker MD may become unable to walk in their 40s or 50s or even later but there are less frequent and more rapidly progressive variants of Becker dystrophy in which this may happen in the 20s or 30s. Over a period of many years some muscles become weak and wasted, especially certain muscles of the shoulders, upper arms and thighs, while others that are less weak are often enlarged - this is usually particularly noticeable in the calf muscles. The muscles of |
| Is there a cure? |
| Unfortunately there is no cure at present. Research is proceeding to try to find a way to induce the muscles to form dystrophin. Any treatment, which may be found to be effective in Duchenne MD, would theoretically be effective also in the Becker type. |
| So what can be done? |
| Active exercise strengthens normal muscle fibres (and the great majority are normal in the early years of Becker MD). It is important to try to keep as fit and active as possible. Regular daily exercise is better than occasional sudden bouts of exertion. Cramps during exercise can bother people with Becker MD at some stage - often especially as a teenager. If they are very troublesome it may be worth experimenting with ‘night splints’ (plastic splints to maintain a gentle stretch of the calf muscles overnight) or with sessions of calf muscle massage or compression with air-filled boots though there is not yet a properly tried and tested treatment for cramps. In the later stages a |
| What about school? |
| Most young men with Becker MD leave school without having had any major muscle problems except that they are usually slow at running in their teens and not very successful at PE or games. However, sometimes if cramps are a particular problem, keeping the school informed can be a good idea. In many cases the problem is recognised and diagnosed at around the age of 20. A few boys with Becker MD also have learning problems, usually of a mild degree but sufficient sometimes to limit their academic success at school. It is important to realise that this is not true of most affected boys, but when the problem does exist it is sensible to recognise and assess it early and to arrange the best possible plan to provide the right educational help. Unlike the muscle weakness, any learning problem will not get worse as the years go by. Despite the fact that to the outside observer BMD may cause relatively few problems in childhood, there is no doubt that some boys can find it a major psychological problem to be poor at sport in a society where boys are especially encouraged to pursue excellence at sport and where sporting heroes are so much in the news. Promoting self worth in this period is a crucial factor. |
| What about work? |
| People with Becker md have been employed in a range of jobs from steel workers to research scientist though occupations requiring a considerable amount of physical activity are not feasible for most people who have Becker md. It is clearly important for people to plan their careers on the basis that their existing physical capabilities are unlikely to improve and will eventually gradually decline. There is no reason why people with BMD should not work - if any special provisions are necessary the local clinic or family care officer can put you in touch with the right people at the local careers service. The important principles are to work for the best possible educational qualifications at school, to make good use of any opportunities for further education and then either to plan a career that will depend as little as possible on physical strength and mobility, or to be prepared to re-train and change jobs appropriately as time goes on. |
| How is Becker MD inherited? |
| The disorder is inherited as an X-linked recessive trait, which means that it affects only males but may be transmitted by unaffected female carriers of the gene to their sons. The sons of carriers each have a 50:50 chance of being affected. The daughters of carriers each have a 50:50 chance of being carriers. The mothers and sisters of affected males may be carriers and may need to be tested. The sons of affected males do not carry the gene and will not be affected or transmit the gene. However, all the daughters of affected males are carriers of the gene and may transmit the disorder to the following generation. |
| How early can it be diagnosed? |
| Once Becker dystrophy is known to affect one male in a family it is possible by simple blood tests to identify it or rule it out in any other boys at risk from birth onwards. In most families, but not in all, prenatal diagnosis is also possible, but this is more difficult and if at all possible the situation needs to be fully assessed before a pregnancy is embarked upon. |
| Can any carriers in the family be identified? |
| Most carriers can be detected if blood samples from their affected male relatives and certain other key members of the family are available for comparison, using techniques of DNA analysis. Although a simpler blood test for creatine kinase is positive in many carriers, only the DNA studies can rule out the carrier state in a woman at risk (for example in the sister of an affected man). However, in a few families, or if the key samples from relatives are not available, it may be possible only to calculate for each potential carrier her statistical risk of having an affected son. |
| ---------------------------------- |
| Support Group |
| Becker United Support Group |
| Web: www.beckerunited.com |
| Email: beckersmd@hotmail.com |
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Emery-Dreifuss muscular dystrophy
| This form of muscular dystrophy was named after Professor Emery in the UK and Professor Dreifuss in the United States, who together first described the disorder nearly 40 years ago. |
| What is it? |
| Like other muscular dystrophies it is a wasting disease of muscle. It usually begins in childhood or adolescence. The features, which make it unique and different from other muscular dystrophies, are the early development of muscle contractures, the distribution of muscle weakness, and the fact that the heart may be affected in a particular way. |
| What are muscle contractures? |
| This is a tightening and shortening of certain muscle groups so that the joints, which are involved, become increasingly difficult to move. Such contractures are common at a late stage in most muscle wasting diseases and result from inactivity. But in this disease muscle contractures develop very early or before there is any marked muscle weakness. |
| What effect do contractures have? |
| In this condition they limit elbow straightening so that the arms are often held in a semi-flexed way, they result in a tendency to walk on the toes, and they limit forward bending of the neck. |
| Which muscles are affected? |
| In the upper limbs weakness affects mainly the shoulders and upper arms. In the lower limbs, unlike most other dystrophies, weakness affects the lower legs first. This distribution of muscle weakness is sometimes referred to as ‘scapulo-humero-peroneal’.At first there is difficulty in raising the arms above the head and lifting heavy objects, and a tendency to trip over carpets. Later on the hip and thigh muscles also become affected so that climbing stairs becomes increasingly difficult, as does rising from a chair without assistance. |
| How is the heart affected? |
| This is affected in a way that is unusual for muscular dystrophy, rather than affecting the heart muscle, it is the electrical wiring (called the cardiac conduction system) that controls the rate at which the heart beats that is mainly involved and is referred to as "heart block". The heart rate is often abnormally slow, palpitations may occur (which feel like "fluttering" in the chest - this is not uncommon in normal individuals and alone would not be a cause for concern), as well as attacks of giddiness and fainting spells. Increasing tiredness and breathlessness may also occur. |
| What can be done if the heart is affected? |
| If the heart becomes affected, and not every person is affected in this way, the doctor may recommend the insertion of a pacemaker. This small gadget is inserted just below the skin of the chest and prevents further problems arising by ensuring that the heart thereafter beats normally. |
| How severe is the disease? |
| In general the condition is less severe than many other forms of muscular dystrophy and though life expectancy may be shortened, many affected individuals can expect to reach middle age or later. However, it is essential that affected individuals be checked at frequent intervals, say every 12 months, to ensure that the heart is not affected. There is evidence that a more severe recessive form also exists. Here weakness is present and progresses rapidly from early childhood, however this is very rare. |
| Can it be treated? |
| Unfortunately there is as yet no cure or effective treatment apart from the insertion of a heart pacemaker when this is necessary. However, having an adequate diet and maintaining good general health are very important as in all muscular dystrophies. |
| Can I improve muscle strength? |
| Regular gentle exercise, which is tolerated without causing stress, is beneficial. But hard physical exercise (weight training for example) should be avoided. It is essential to eat a well balanced diet, to include plenty of roughage and to avoid becoming overweight since this will only overburden the already weakened muscles. |
| Can surgery help? |
| Division of the heel cords can be useful in helping walking. Other operations can be indicated in individual cases where expert advice from a neurologist and orthopaedic surgeon should be sought. Because the heart may be affected and could complicate an operation, the anaesthetist must be told of the diagnosis before any operation is undertaken. |
| Will I become disabled? |
| The condition progresses very slowly over the years (except for the very rare recessive form), and it may be that later in life a wheelchair may be required. |
| Job prospects |
| As in other slowly progressive muscle diseases, in the early stages most occupations could be considered (a driving licence however maybe subject to a medical examination). But since physical disability increases with age, some form of sedentary occupation is preferable in the long term. |
| Can it affect my children? |
| The condition is inherited and can therefore affect other members of the family. In many families it is inherited as a sex-linked (X-linked) trait and therefore only affects males and is carried by unaffected females. All the sons of an affected male will be unaffected but all his daughters will be carriers. With regard to the offspring of a woman who is a carrier, on average each of her daughters has a 50:50 chance of also being a carrier, and on average each of her sons has a 50:50 chance of being affected. The condition can also be inherited as an autosomal dominant trait, which affects both males and females. Here the genetic risks are different. As in all autosomal dominant disorders on average each son or daughter of an affected parent has a 50:50: chance of also becoming affected. In the case of the recessive form, both parents are normal but there is a 1 in 4 chance of any future children also being affected.To make matters even more complicated, sometimes in x-linked and dominant cases there is no family history of the disorder, only one individual in the family being affected. In these cases the disease has arisen as the result of a new mutation in the affected individual but who may then later transmit the disorder to his or her children. For these various reasons it is very important to seek the professional advice of a neuromuscular specialist or medical geneticist if you are at all concerned about the risks to your children and other relatives. |
| What of the future? |
| This is much more hopeful than in the past. Not only through the use of pacemakers in cases with heart disease, but the genes responsible both the autosomal dominant (codes for lamin A/C) and the X-linked forms of Emery-Dreifuss muscular dystrophy (codes for emerin) have been identified. This information is vital in the search for an effective treatment and also for prenatal diagnosis. |
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Limb-Girdle Muscular Dystrophy (LGMD)
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Facioscapulohumeral Muscular Dystrophy (FSH or FSHD)
| What is it? |
| FSH is a muscle wasting condition, caused by a genetic fault, which may be affecting the regulation of the level of many of the different proteins in muscles. |
| Why this name, and are there others? |
| The name describes the usual distribution of weakened muscles: ‘facio’=facial; ‘scapulo’=shoulder blade; ‘humeral’= upper arm. Landouzy-Dejerine and facioscapuloperoneal muscular dystrophy are two previously used terms. Also, some people with a diagnosis of scapulohumeral or scapuloperoneal syndromes may have this condition. However, the legs can also be affected. |
| How rare is it? |
| It is probably the third most common muscular dystrophy (after Duchenne and myotonic dystrophies), although its frequency may vary in different places and quite possibly in different racial groups. Estimates of frequency have varied from one in about 400,000 to one in 20,000. In Britain, the frequency is at least one person in every 50,000, and probably closer to one in 20,000, accounting for between about 1200 and 3000 cases in all. |
| What causes it? |
| It is a genetic condition, present from when or soon after egg and sperm come together at conception. Normally, at a particular site on the gene map, each of us has many copies of a particular sequence of genetic instruction (DNA), arranged like a train of identical carriages. FSHD is caused when the number of copies is reduced below a certain level, like a train having too few carriages. In some way this seems to influence the production or assembly of several of the protein components of the affected muscles. |
| How severe or mild is it? |
| The degree of weakness or disability can vary quite widely between different affected members in a family, but can show even greater variation between people in different families. For some, it can result in weakness not only of |
| Are men and women affected equally? |
| We now know that, on average, men do tend to show more weakness and from a slightly earlier age than women. The reason for this is not yet clear. Within large families, and therefore excluding the most severe cases, women are more likely to be less severely affected and so could be unaware that they have inherited the condition. |
| What are the mildest signs that someone is affected? |
| Within the context of a family history of FSHD, weakness of facial muscles can be suspected if the eyes remain slightly open when asleep, particularly in young children, or if the eyelids cannot be screwed tightly enough to bury the eyelashes. Difficulties in pursing the lips to whistle or to |
| Does FSHD affect lifespan? |
| Generally speaking, lifespan is not affected, except perhaps in the most severe cases with greatly impaired mobility and consequent greater risk of chest infections. There are some recent reports suggesting an increased association with heart rhythm disorders, but only in a few cases, and these are responsive to appropriate medication. Because of these reports, adults with FSHD would be advised to see their GP (or hospital doctor) every few years for a simple heart check. |
| Will I become disabled? |
| The earlier in life the weakness appears the greater its eventual severity. Nevertheless, the progression of either arm or leg weakness in the individual can be hard to predict. Although the legs are affected to some degree in over 50% of people, for those in whom this does not become evident until early adulthood, even an eventual requirement for a wheelchair is unlikely.To some extent, knowledge of the size of the DNA rearrangement (i.e. the number of repeat units remaining) in a person with FSHD can give a broad guide as to whether the course of the condition would be expected to be relatively mild or more severe. One fairly common feature of FSHD is an asymmetry of weakness: an uneven distribution of muscle weakness where one side of the body is more affected than the other (particularly early on). This is often evident in the shoulders, usually with the right side to be the first one involved in right-handed people. |
| In what way are the legs affected? |
| Early weakness at the ankles causing ‘foot drop’ is not uncommon. Some degree of weakness at the knees or hips develops by middle age in over 50% of people. Together with weakness in the back muscles, this can result in a typical backward-leaning and high-stepping gait, although only 10-20% ever requires a wheelchair. |
| Can any other problems be anticipated? |
| In some of the earliest childhood onset cases, learning difficulties and epilepsy have been reported. Hearing loss and specific problems with blood vessels at the back of the eye have been found, and although this rarely causes visual problems, a periodic eye check may be useful. It is still uncertain whether these rare features are generally associated in mild degree with FSHD, or are limited to a few more severe cases.Muscle pain is unfortunately a quite frequent complaint accompanying FSHD, often in the early stages. This may relate to inflammation within the muscles, which seems to occur more in FSHD than other muscular dystrophies. Treatment with simple analgesia combined with anti-inflammatory agents is usually tried, but the effectiveness for relief can vary. Further studies are needed. |
| How is it inherited? |
| A separate gene determines each hereditary characteristic or function. These genes are packed together into chromosomes like beads on a string. There are two copies of each chromosome (excepting the X and Y chromosomes in males), and hence two copies of each gene (a pair), coming one from each parent. The ‘gene’ for FSHD is at one end of each copy of chromosome 4. In FSHD, one copy of this particular pair is faulty (part of it is missing, which is referred to as a ‘deletion’). Hence there is a 50:50 (1 in 2) chance for each of the offspring of an affected parent to inherit the faulty copy, resulting in FSHD. They also have an equal chance of inheriting the good copy (resulting in no risk for these individuals or their descendants of being affected by FSHD). This pattern of inheritance is called ‘autosomal dominant’. |
| With completion of the ‘human genome project’ has the gene causing FSHD been identified? |
| Unfortunately the situation is a little more complex than as discussed (in answer 12.) above. Amongst genetic conditions, FSHD seems so far to be unique in that the genetic fault (‘mutation’) is the reduction (‘deletion’ at one end of chromosome 4) of multiple copies of a repeated sequence of DNA (likened to reducing the number of carriages in a train). This DNA change, which is the dominantly inherited factor, is probably exerting an effect on the way that the function of many genes is regulated in muscle, and particularly in the muscles of the face and shoulder girdle. Hence, there may be many ‘genes’ which are involved in causing FSHD, but for which the controlling dominantly inherited mutation always occurs at the same place on chromosome 4. Much current research in FSHD is aimed at trying to define this link. |
| Can FSHD be diagnosed from a blood sample? |
| The DNA mutation causing FSHD can indeed be recognised from a blood sample in most people with this condition. However, interpretation of the test is not always easy, and the DNA sample will need to be forwarded to one of a few molecular genetic laboratories able to offer this. In individual cases it can be harder to exclude the diagnosis than to confirm it, although both are usually made easier if blood samples are also taken from both parents of a possible affected person.In families where there are several people known to be affected, confirmation of diagnosis, or genetic prediction for an individual family member, will almost always be possible if blood samples are collected from several of the affected people. |
| Is there always a family history? |
| A person diagnosed with FSHD, particularly if this is in early childhood, may have a fresh mutation (i.e. they have not inherited it from either of their parents). More often, however, a person diagnosed with FSHD will have inherited the faulty gene from one of his or her parents. It may be that a newly diagnosed person finds that there is a family history, but that this had not been recognised before because the symptoms of other family members had been very mild, or had been misdiagnosed. We now also know that in a significant proportion of even quite early onset cases in children, who appear to be the first ones in a family, one of the parents can show the same FSHD mutation in some of their cells but not in others. This ‘mosaic’ situation in the parent may not give any symptoms in them, but does mean that further children of theirs would have a risk of being affected. We would therefore always recommend that both parents be invited to provide blood samples for DNA study if they wish to know about potential risk to future children. In other cases genetic testing may help resolve any uncertainty over the affected status of a young adult. Family members or couples seeking further information should refer to their local Clinical Genetics Service. |
| How severely affected would my sons and daughters be? |
| The age at onset of symptoms, and hence the severity of FSHD, seems to correlate broadly with the extent of the DNA rearrangement on chromosome 4, which, once it has arisen, remains a fixed size in a family. Thus there will be some families where FSHD will always tend to be quite severe, and others where it will always be relatively mild. However, there can still be considerable variation within a family for severity and age at onset. Partly, this is due to differences between men and women. Although men and women develop the same symptoms, males tend to develop these earlier, and be more severe at a given age than females. By age 30 years, just about all males with FSHD exhibit symptoms, but only two-thirds of females do. We now know that some people (particularly men) with average or mild presentations of FSHD, may, if they are the first cases in a family, have a mixture of normal and FSHD-type cells and their offspring, who have inherited the FSHD mutation, would do so in all their cells, and therefore present earlier and more severely.Data from many families suggests that offspring inheriting the faulty gene are likely to be affected from a similar young age and at least as severely as occurred in their affected parent, although in large families affected daughters with FSH might be milder than their fathers. |
| At what age does it usually start? |
| This is dependent on the extent of the DNA rearrangement. In large families with several affected members, an affected person usually first becomes aware of muscle weakness in teenage years or early adulthood, when he or she experiences difficulty in raising one or both arms, or notices prominent shoulder blades or wasting of upper arm muscles.In the more severe cases, which are often the first ones in a family and arising from a new mutation giving a small residual DNA repeat length, impaired movement of facial muscles, particularly around the mouth, can be evident by early childhood, followed by the shoulder girdle and upper arm weakness. In these children progressive weakness of the legs can start to develop by teenage years and lead to the need for a wheelchair. By contrast, in the mildest families, with the largest residual DNA repeat lengths, people inheriting the condition may remain unaware of symptoms until even late in adulthood. |
| If I have no symptoms can I still carry the gene and pass it on to my children? |
| If the person with FSHD has been affected from childhood, it is very unlikely that an adult relative (say a brother or sister) who is unaware of any symptoms, could ‘carry’ the faulty gene or pass on FSHD to their children. The parents of the affected child are an exception, as they could be ‘carrying’ the mutation but in only some of their cells, and hence pass this on to more than one child.For people from families where several relatives or a parent have FSHD, one cannot give the same level of reassurance except following DNA testing. In these situations, many people ‘at risk’ may be affected only mildly, and are unaware of the abnormal signs that are present. Although some degree of reassurance may be possible if examined by a doctor well familiar with the condition, we now know that up to one-third of adult women carrying the milder mutations for FSHD, and a probably much smaller proportion of men, may not be showing any definite sign of the condition. Therefore, the answer to this question can only be given reliably following DNA testing. |
| If one of my children is affected, but another seems clear, is he or she likely to have ‘escaped’ inheriting FSHD? |
| If the apparently unaffected child is several years beyond the age at which the affected one first presented with symptoms, it becomes very likely that they have not inherited the condition. This is particularly so if the affected child is the first-presenting person in the family, and if DNA testing has shown that their condition has arisen from a new DNA rearrangement (a new mutation) not present in a DNA sample from either parent. However, if either parent is clinically affected or carries the mutation, only DNA testing can give reassurance. If a child has no signs of FSHD, requests for DNA testing would normally be refused until the child is of an age to choose this for themselves. |
| Can I avoid passing the faulty gene on to my children? |
| Accurate pre-natal testing, performed by chorion villus biopsy (CVS), usually at 11 weeks gestation, is now available to most couples who would wish this, and whose offspring would be at risk of FSHD. It is essential that genetic (DNA) tests be performed first on blood samples from the affected parent or child to define the DNA mutation in that family. Blood samples would usually be required from both parents, and in some cases from other affected relatives. The CVS procedure is now widely available, although the tissue sample obtained would be forwarded to one of a few specialist genetic laboratories. Couples considering this should consult with their local genetic service that would advise accordingly, preferably prior to becoming pregnant. |
| Can I improve muscle strength? |
| There are no cures or specific drug treatments. Regular gentle exercise (especially swimming) is beneficial. It is essential to keep your weight down (through diet if necessary) in order to reduce stress on already weakened muscles. If exercises are undertaken to increase muscle strength any build-up should be done gradually. |
| Can surgery help? |
| The scapular muscles, which attach the shoulder blades to the chest, are often very weak and this leads to difficulty in lifting the arms. The operation of scapular fixation (fixing the shoulder blades to the ribs at the back) has enabled some people to regain more use of their arms. Because prolonged immobilisation of limbs could increase the weakness of disused muscles, combined assessment from a neurologist and an orthopaedic surgeon prior to operation is advised. For people who have troublesome inflammation of the eyes as a result of them if they are remaining open at night, surgery to bring the eyelids closer can be offered if artificial tears alone are insufficient. |
| Are anaesthetics a risk? |
| There is no known risk, but you should be sure that the anaesthetist is aware of your diagnosis prior to operation. |
| Should I declare it on insurance forms? |
| Once the diagnosis has been made you have an obligation to declare it when requested. As there is no significant effect on life span, you should ask your doctor for a letter of support if you run into problems. When applying for a driving licence, especially HGV or PSV, this may be issued for a limited duration, with renewal subject to satisfactory medical examination. |
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| Support Group |
| The FSH Support Group offers support and encouragement to families and individuals that have FSHD. |
| For further details please contact: FSH Support Group C/O Muscular Dystrophy Campaign 61 Southwark Street London SE1 0HL |
| Tel: 0800 652 6352 Fax: 020 7401 3495 Web: www.fsh-group.org |
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Myotonic Dystrophy (MMD)
| What is myotonic dystrophy? |
| People with myotonic dystrophy, like those with other dystrophies, experience muscle weakness and wasting which is usually progressive. There are many differences, though, in the type of problem that people with myotonic dystrophy may have. These may include the following: Types of muscles involved are usually in the face, jaw and neck area; the large, weight-bearing muscles of the legs and thighs are much less affected. Rate of deterioration is commonly slow, with little change over a long period; some people never have significant muscle disability. Muscle stiffness or 'myotonia' is characteristic, especially affecting the hands. Involvement of other body systems is frequent; associated problems may include cataracts, disturbance of heart rhythm, hormonal problems and, in children, learning difficulties. Age at onset is very variable. Symptoms may appear at any time from birth to old age. |
| How is myotonic dystrophy inherited? |
| This condition follows a 'dominant' inheritance pattern, which means that on average half of the children of an affected person are themselves affected. Both men and women are equally likely to be affected and to pass on the disorder, but affected women are more likely to have a severely affected child. In general (though not always) the disorder tends to be more severe in successive generations. Most healthy adult relatives will not be likely to develop or pass on the disorder, but a careful assessment by an expert is important as mild features can easily be missed. Genetic testing on a blood sample for such relatives can now provide greater certainty, but should always be done with full information as part of genetic counselling. Genetic testing of healthy young children is not recommended. Very few cases of myotonic dystrophy occur 'out of the blue'. Almost always, one parent proves to be affected, often very mildly. Some parents (or grandparents) prove to carry a very slight genetic change that will never give them symptoms. Careful study of the whole family often shows more members to be affected than would appear likely at first. |
| What is the cause? |
| The changes in muscle and other body systems in myotonic dystrophy are now known to result from a specific genetic change (mutation) which in most cases involves a gene on chromosome number 19. The same change occurs in patients world-wide, but it is variable in extent, even in a single family, because it is unstable. The length of a particular ‘triple repeat sequence’ (CTG) is expanded in patients and this may vary from a slight expansion in mildly affected individuals to a very large one in severely affected children. Until recently it has not been clear how genetic change causes the condition: the most likely mechanism is now thought to be that the expanded repeat is converted normally into the next stage (RNA), but then is unable to leave the cell nucleus. As a result of this trapping, a range of other types of RNA are affected, as are the protein they produce, which helps explain how a single genetic change can affect different body processes.‘PROMM’ (proximal myotonic myopathy) and type 2 myotonic dystrophy. An important recent advance is the recognition of a second disorder with features resembling myotonic dystrophy.The muscle weakness tends to differ in distribution (more in proximal limb muscles, less in the face) and myotonia is often mild or absent. Cataract and heart involvement occurs as in myotonic dystrophy. It is now clear, that this condition (PROMM: proximal myotonic myopathy), is the same as some rare families thought, clinically, to have myotonic dystrophy but not showing the expected mutation and termed ‘type2 myotonic dystrophy’ or ‘DM2’. The gene involved has now been isolated on chromosome 3. Although quite different to that for myotonic dystrophy it contains a very similar, expand repeat (CCTG), which is likely to explain the clinical similarity of the two disorders. We are still learning about the details of this condition, but it is probably uncommon and accounts only for a small proportion of patients thought clinically to have myotonic dystrophy. |
| Future advances |
| The research advances of the past 10 years have increased our understanding to the point where we can begin to see future possibilities for preventing or limiting the damage to muscle and other systems that occurs in myotonic dystrophy. In particular the genetic changes can now be re-produced in mouse models, which could allow the study of the effects of drugs and other agents that might be too untried to use safely on humans initially. It is difficult to predict how rapidly this work will progress, but possibilities exist now that were not present until very recently. |
| Problems and management |
| Although no 'cure' for myotonic dystrophy exists at present, there is a lot that can be done to help those affected. Indeed, since many doctors are unfamiliar with the condition, it is essential that people who have myotonic dystrophy are themselves aware of the problems and dangers they may face. Some of these are mentioned here; of course they rarely all occur in one person, and many people have few symptoms, but it is important to be aware of them. Operations and anaesthetics can be risky, even for mildly affected people. It is most important that any surgeon or anaesthetist should know a person has myotonic dystrophy before surgery is planned. Problems usually occur when doctors are unaware of the disorder; if care is taken, surgery is usually safe. A person may wish to wear a bracelet or locket stating their condition. A specific warning card is available that can be carried in a wallet. This can be obtained from the Myotonic Dystrophy Support Group (address below). 'Keep out of trouble' is a good motto for those with myotonic dystrophy. A minority of people can develop heart problems, which are commonly treatable but can be serious if ignored. A regular cardiogram (ECG) is wise.Some people who have myotonic dystrophy may have more trouble with other body systems than they do with their muscles. A symptom that appears quite unrelated may be connected. Excessive daytime sleepiness, swallowing difficulties and a range of bowel symptoms are examples. It is important that people with myotonic dystrophy should make sure that whoever treats them is aware that they have the condition and knows the wide range of associated problems. If troublesome, muscle stiffness due to myotonia can be helped with certain drugs. Children with myotonic dystrophy may have learning problems at a time when there are no muscle complaints. Again, be sure that myotonic dystrophy is borne in mind if this disorder is in the family. Affected women need careful management if undertaking a pregnancy. Not only is there a risk of a baby being severely affected, but problems in pregnancy and delivery may affect the mother. Equipment for mobility and adaptations in the house can be very useful, though few affected people need a wheelchair. Weak neck muscles make a sound head-rest essential when driving. |
| In summary |
| In summary, we now know a lot about myotonic dystrophy, but still have a long way to go. Helpful genetic counselling and family testing are now possible, but the best approach to treatment is to know about the condition, its risks and complications, and to be sure that your doctors do too. |
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| Support Group |
| Myotonic Dystrophy Support Group: |
| Contact: Mrs Margaret Bowler |
| 35A Carlton Hill |
| Nottingham NG4 1BG |
| Answerphone: 01159 870 080 |
| Web: www.myotonicdystrophysupportgroup.co.uk |
| Email: mdsg@tesco.net |
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Oculopharyngeal Muscular Dystrophy (OPMD)
| It has been recognised for many years that some patients with muscle disease have particular problems with the muscles around the eyes, although other parts of the body can also be involved. Whilst research is continuing, it appears that most of these patients have either oculopharyngeal muscular dystrophy (OPMD), the subject of this page, or mitochondrial chronic progressive external ophthalmoplegia (CPEO). Often, when patients first present, it may not be clear whether the patient has OPMD or CPEO, but specific investigations can differentiate between the two.The medical terms relating to these conditions may cause the lay person some confusion. They include: ptosis, external ophthalmoplegia, diplopia and dysphagia. |
| Ptosis - this describes drooping of the eyelids due to weakness of the muscle that normally lifts up the eyelid. |
| External ophthalmoplegia - this means weakness and restriction of muscle movement around the eye (external to the eye). It shows as slowness and incomplete range of movement of the eyes, and includes the eyelid muscle weakness that causes ptosis. These problems typically progress very slowly, hence the term 'chronic progressive external ophthalmoplegia'. Diplopia - this simply means double vision and occurs when the eye muscles on each side are not affected equally, so that the eyes point in slightly different directions. Dysphagia - this means difficulty in swallowing. When mild, it may simply be a feeling of food sticking in the throat, but patients with severe dysphagia may not be able to swallow at all and can even choke on their own saliva. |
| Symptoms and signs |
| Although the abnormal gene causing OPMD is present from birth, patients do not usually develop symptoms until the fifth or sixth decade of life. The first sign of the disorder is usually ptosis, but occasionally it is dysphagia. Very slowly, over many years, these problems progress. There is progressive restriction of eye movements and in rare cases this can lead to diplopia. The increasing ptosis may lead to the eyelid covering the pupil and impairing vision, and in an effort to compensate for this the forehead muscle becomes overactive, trying to help to lift up the eyelids, giving a frowning appearance, and the patient adopts a rather characteristic posture with the head tilted backwards.Dysphagia, which is initially mainly for solid and dry foods, progresses slowly and eventually even swallowing fluids, including saliva, may become a problem. If dysphagia is severe there is a danger of aspiration (food, drink or saliva "going down the wrong way" - into the chest rather than stomach) which greatly increases the risk of a chest infection. After many years the patient may become aware of limb weakness, first around the shoulders and later around the hips. This is usually relatively mild but can occasionally be severe and disabling, many years after the first onset of symptoms. |
| Management |
| There is no specific treatment for OPMD, but much can be done to help the main symptoms of ptosis and dysphagia. Glasses can be fitted with fine metal bars (ptosis props) that lift up the drooping eyelids. If these are unacceptable, and if the ptosis is severe, surgical elevation of the eyelids can be very successful – several procedures are possible and should be tailored to the individual patient.Mild dysphagia can be helped by suitable attention to the consistency of the diet (with a dietician's advice) and by exercises taught by a speech therapist. In more severe cases, a relatively minor operation called cricopharyngeal myotomy, which cuts one of the throat muscles internally, can be valuable. Another approach that is sometimes helpful is to inflate a balloon to dilate the gullet. But as for all surgical procedures there are potential hazards and the final choice of treatment depends upon many individual factors. Recently there have been a few reports of the use of botulinum toxin injections; rather than cut or stretch a muscle, the toxin relaxes the muscle and that can aid swallowing. However, further studies are needed to see whether this will prove to be a useful long-term treatment. If the dysphagia is preventing adequate nutrition or there is a risk of aspiration pneumonia, then alternative methods of feeding can be used. The most acceptable, in the long term, is gastrostomy. A minor operation is used to pass a tube through the front of the abdomen directly into the stomach. Patients and their relatives find this easy to manage at home. If the normal diet is compromised, then a dietitian can offer advice with respect to supplements which can help to maintain adequate nutrition. Physiotherapy may be useful to help patients cope with limb weakness, although this is usually mild, and to reduce the risk of chest problems. |
| How is OPMD inherited? |
| In almost all cases the condition is inherited as an autosomal dominant disorder (see figure below), which means that each child of an affected individual has a 50% risk of inheriting the same condition. It is now possible, through a blood test, to determine whether somebody has inherited the abnormal gene (called PABPN1) but that is not always terribly helpful. Even if somebody has inherited the abnormal gene, it is impossible to predict when, if ever, they will develop symptoms. Such testing should only be performed after detailed discussion with a suitably experienced neurologist or genetic counsellor. |
| Diagnosis |
| The diagnosis can be confirmed by a blood test that identifies the underlying genetic abnormality. Electrical tests (EMG) and muscle biopsy are now rarely necessary. |
| Is there any research being conducted into OPMD? |
| The genetic fault that causes OPMD was identified in 1998. Although this was a very important discovery, which has given us a simple diagnostic test, it is likely to be some considerable time before the research allows us to identify a specific treatment for this condition. In the meantime, there is a great deal of research trying to identify how the genetic fault causes the physical problem. Since 1998 over 100 research papers on OPMD have been published. Whilst none of these have yet led to a major change in management, they should be regarded as the building blocks for progress in the future. |
| Mitochondrial chronic external ophthalmoplegia (CPEO) |
| As mentioned above, this condition can be confused with OPMD. It is often sporadic (i.e. occurs in an individual with no family history of a similar condition) but occasionally is inherited so that there is a history of similarly affected relatives. In CPEO the restriction of eye movements tends to be much more severe than in OPMD, but diplopia is still uncommon. As in OPMD, ptosis can be marked. Dysphagia is less common in CPEO than OPMD. Limb muscle weakness can be similar to that in OPMD, but may be more severe, and associated with exercise-intolerance.Mitochondrial disorders can also affect other organs giving rise to deafness, diabetes, heart problems, and brain problems including epilepsy and dementia. |
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Distal Muscular Dystrophy (DD) (Miyoshi)
| Definition |
| A class of muscular dystrophies that primarily affect distal muscles, which are those of the lower arms, hands, lower legs and feet. Muscular dystrophies in general are a group of genetic, degenerative diseases primarily affecting voluntary muscles. |
| Cause |
| A mutation in any of at least eight genes that affect proteins necessary to the function of muscles. |
| Onset |
| childhood to adulthood |
| Symptoms |
| Weakness and wasting of muscles of the hands, forearms and lower legs. |
| Progression |
| Slow progression; not life-threatening. |
| Inheritance |
| May be autosomal dominant, meaning a faulty gene is inherited from one parent; or autosomal recessive, occurring when a faulty gene is inherited from each parent. |
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Congenital Muscular Dystrophy (CMD)
| What is congenital myotonic dystrophy? |
| Congenital myotonic dystrophy is the early childhood form of myotonic dystrophy (also known as Steinert's disease). Usually in myotonic dystrophy the symptoms begin to show in childhood or later in life, but symptoms of congenital myotonic dystrophy are evident from birth. It occurs only when the mother already has myotonic dystrophy (although she may not be aware of this) and she passes it on to the child in a more severe form. Congenital means "from birth" because the condition is usually identified at birth or soon after; myotonic means "involving muscle stiffness"; and dystrophy, "muscle wasting and weakness". (NB Congenital myotonic dystrophy is not the same as congenital myopathy or congenital muscular dystrophy. For more information about these or other conditions please contact the Muscular Dystrophy Campaign’s Information Line.) |
| How common is it? |
| This condition is rare, but a family affected by congenital myotonic dystrophy is not alone: there are many other families, groups and specialists who can be contacted and who offer support, advice and information. |
| What are the symptoms? |
| Often babies with congenital myotonic dystrophy have problems with breathing after delivery and may need to be helped, using a ventilator. Suction, to remove any secretions in the lungs may also be necessary. Respiratory problems may continue after the birth, and can be very severe and life threatening, especially if the baby is premature. Once the neonatal period (28 days after birth) has passed, the respiratory problems tend to improve. The baby is often floppy which means that she or he has poor muscle tone. This usually improves with age. It is important that physiotherapy should be practised on the baby from a very young age to help with breathing and lung function, and to encourage movement and strength.The baby may have poor head control. There is commonly Older children tend to have poor motivation and concentration and are easily tired. If a child can attend therapeutic playgroup, this can have an important effect on stimulating learning and development, which will stand the child in good stead later in life. The motor milestones (physical achievements such as sitting unaided) and the intellectual milestones which a healthy child reaches by a certain age, tend to be delayed in a child with congenital myotonic dystrophy.here may be speech difficulties, particularly with clear pronunciation. Speech therapy can be of help. A baby often has swallowing and therefore feeding difficulties. She or he may regurgitate food, have bouts of colic and need food supplements. A haberman feeding teat can be helpful for some babies. Some babies may need a feeding tube (nasogastric tube) or even at times of illness a drip (intravenous infusion) to help with feeding. Some children have a squint, and very occasionally children may have impaired vision. Children commonly have club feet (talipes). This may be mild or severe; both improve with physiotherapy but the severe form will require corrective surgery. Physiotherapy is important, with passive stretching to help with the foot problems. The development of control over the bladder and bowel are sometimes delayed. Bladder control usually improves to become normal but bowel problems especially constipation may be persistent due to the muscle of the bowel wall being involved. As you can see, youngsters with congenital myotonic dystrophy may have more trouble with other body systems than they do with their muscles. A symptom that may appear to be totally unrelated may in fact be connected. It is important that whoever treats them is aware of the wide range of associated problems. |
| How early is diagnosis made? |
| During her pregnancy, a mother of a child with congenital myotonic dystrophy may have noticed that the baby was not moving around in the womb as much as normal, and had reduced fetal movements. She may have had hydramnios (excessive amounts of amniotic fluid) and premature labour. The mother may not be aware of having myotonic dystrophy herself until after the birth of her affected baby. At the time of delivery, (if the baby is known to have congenital myotonic dystrophy antenatally), staff should be aware that the baby may need immediate intensive care and the parents should be made aware of the procedures. |
| How severe or mild is it? |
| Congenital myotonic dystrophy can vary considerably in severity from child to child. If a child is diagnosed with the condition soon after birth, symptoms are likely to be severe. In these cases, special shoes, walking aids and calipers may be needed. A few affected children need to use a wheelchair. Sadly, congenital myotonic dystrophy can be fatal, especially in the early weeks of life, but a child who lives beyond his or her first birthday is likely to live to become an adult. |
| How is congenital myotonic dystrophy inherited? |
| The condition follows a 'dominant' inheritance pattern which means that on average, half of the children of a woman with myotonic dystrophy will be affected themselves. It affects both sexes, but the mother is usually the affected parent. |
| Is there a treatment or cure? |
| Not at present, however, physiotherapy and occupational therapy are very important ways of improving or maintaining a child's physical condition, diagnosis is increasingly accurate, pre-natal testing is available at an early stage of pregnancy.In 1992 Muscular Dystrophy Campaign researchers pin-pointed the genetic defect which causes myotonic dystrophy. This was a crucial milestone because it allows researchers to study the gene and the protein(s) it codes for and it is only by understanding the way that the gene works that they can begin to think of ways of developing a treatment. We now know that the type of genetic defect responsible for myotonic dystrophy is virtually identical in all those so far tested which indicates that the condition may have sprung from a single original change in the gene that happened many thousands of years ago. The gene responsible for myotonic dystrophy seems to govern an important protein, which has an effect on many of the body's functions. This is why myotonic dystrophy has so many varied effects. It has been shown that the larger the disruption of the gene, the more severe the symptoms are likely to be. Although there is some overlap, three main categories can usually be predicted from the genetic studies from very mild, barely noticeable symptoms to average and very severe symptoms. Researchers based in Cardiff and London have also discovered that in very rare cases (2-3%) the genetic mutation actually decreases through the generations. The severity of myotonic dystrophy tends to increase through the generations (except in rare cases mentioned above). This means that a grandfather might only have cataracts but his grandchild could be very severely affected with the congenital form of myotonic dystrophy. It is very important therefore, to trace relatives of someone affected by myotonic dystrophy in order to give them the option of genetic counselling. |
| Are anaesthetics a risk? |
| Operations and anaesthetics can be risky. It is very important that any surgeon and anaesthetist should know a child has congenital myotonic dystrophy before surgery is planned. Problems usually occur when doctors are unaware of the disorder; if care is taken, surgery is usually safe. Patients may wish to wear a bracelet or locket stating their condition. A specific warning card is available that can be carried in a purse or wallet. This can be obtained from the Myotonic Dystrophy Support Group (address below). |
| Can a child with congenital myotonic dystrophy have the usual inoculations? |
| Yes |
| Will the condition improve? |
| It often improves during childhood but may deteriorate again later in life. |
| ---------------------------------- |
| Support Group |
| Myotonic dystrophy and congenital myotonic dystrophy are fairly rare conditions and ones about which people often have not heard. Parents of a child with congenital myotonic dystrophy can often feel rather isolated. However, they will find that there are many people in similar situations that have already dealt with problems they are encountering. A national support group is run by and for families affected by myotonic dystrophy. |
| 35A, Carlton Hill Carlton, Nottingham NG4 1BG Tel: 0115 987 0080 Web: www.myotonicdystrophysupportgroup.co.uk |
| Email: mdsg@tesco.net |
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