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FSH Muscular Dystrophy  43

I have muscular dystrophy and, if I’m honest, it’s a bitch and I fucking hate it. I still have a decent (albeit twisted) mind and enough friends and family to ensure an active social life, though. So what if I can’t get up those stairs? There’s bound to be someone around who could drag me up by my hair. Using a wheelchair virutally guarantees a good view at any live event and I can park almost any where I want. But, I still hate it. People often say to me “You cope really well with being disabled” and I feel like screaming “WHAT FUCKING CHOICE DO I HAVE?!?”, but I usually just smile and say “Thanks”.

I was diagnosed in 1985, just before my twelfth birthday; my family took it a lot harder than I did at first, my mum especially. I then saw several doctors at several hospitals - ranging from the incredibly unsensitive Dr. Green at Birmingham to the very pleasant Professor Edwards and Dr. Coatly at Liverpool - before deciding to just get on with my life. I now see Dr. Quinlivan on a yearly basis at the orthopaedic hospital in Oswestry for monitoring purposes.

I live in a rented bungalow with my personal assistant and have many useful gadgets and appliances to allow some independence. I stood unaided for the last time on my 30th birthday, back in 2003 - it was painful and scary (I was constantly worried about succumbing to gravity) so I gave it up then before I hurt myself. Life since has been much the same with only the ability to use a toilet whilst out and about being affected.

The main purpose of this is to answer a lot of people’s questions. When I meet people they invariably get round to asking me about why and how I’m disabled and, while I don’t mind talking about it, after saying the same thing five times at a party it gets boring. So, it’s time to educate people so that less drinking and chatting-up time is wasted at those all-important social occasions.

There are several forms of muscular dystrophy - this page is about the form I have, facioscapulohumeral (big word). All the questions and answers below are taken from a leaflet written by Dr. P W Lunt, the Consultant Clinical Geneticist at Bristol Children’s Hospital, and was distributed by the FSH-MD Support Group and provides information for sufferers and non-sufferers alike. I have to admit, there are some things here that I didn’t know until I read the leaflet.

Questions

1. What is it?
2. Are there any other names?
3. Why this name?
4. How severe or mild is it?
5. What are the mildest signs that someone is affected?
6. Does this affect life-span?
7. Will I become disabled?
8. In what way are the legs affected?
9. How severely affected would my sons and daughters be?
10. At what age does it normally start?
11. How is it inherited?
12. Is there always a family history?
13. Can FSHD now be diagnosed from a blood sample?
14. If I have no symptoms can I still carry the gene and pass it on to my children?
15. Can I avoid passing the faulty gene on to my children?
16. How common is it?
17. Can I improve muscle strength?
18. Can surgery help?
19. Are anaesthetics a risk?
20. Should I declare it on insurance forms?
21. Can any other problems be anticipated?
22. Is the genetic fault known?
23. What are the current areas of research?

1. What is it?

It is a muscle wasting condition, caused by a gentic fault affecting one or more of the proteins of the muscles.

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2. Are there any other names?

Yes. Landouzy-Dejerine and fascioscapuloperoneal muscular dystrophy are some previously used terms. Also, some people with a diagnosis of scapulohumeral or scapuloperoneal syndromes may have this condition. The gene involved is termed FSHD, which for convenience, is also used hereafter on this page as an abbreviation for the clinical condition.

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3. Why this name?

The name describes the usual distribution of weakened muscles: ‘facio’ = facial; ‘scapulo’ = shoulder blade; ‘humeral’ = upper arm. However, the legs can also be affected.

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4. How severe or mild is it?

Between one in ten and one in five people require a wheelchair in later life, and at its most severe weakness of the neck, forearms, wrists and fingers can also occur. However, up to one third of those inheriting the gene can go through life without it having any significant effect on them. The majority of affected people come between these two extremes, with the more severe presentations tending to be where FSHD has occured by new mutation for the first time in a family.

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5. What are the mildest signs that someone is affected?

Weakness of facial muscles can be suspected if the eyes remain slightly open when asleep, of if the eyelids cannot be screwed tightly enought to bury the eyelashes. Difficulties in pursing the lips to whistle, or in blowing up balloons are suggestive of the condition. A baby or young child may show little facial expression. Later, excessive aching around the shoulders, rounded or ‘dropped’ shoulders and thin upper arms may also add to the suspicions. Many people are first aware of signs only in one shoulder, this usually being on the right side if they are right handed.

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6. Does this affect life-span?

The condition does not affect the muscles of the heart or those to do with breathing, and therefore does not usually affect life-span.

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7. Will I become disabled?

The earlier in life the weakness appears, the greater it’s eventual severity. However, progression of either arm of leg weakness in the individual can be very hard to predict. Up to one in five people with FSHD may require a wheelchair, but although the legs are affected to some degree in over 50% of people, for most this does not become evident until early adulthood and even an eventual requirement for a wheelchair is then unlikely.

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8. In what way are the legs affected?

Early weakness at one or both ankles, causing ‘foot drop’, and a characteristic high-stepping gait with ‘throwing’ of the leg is not uncommon. Some degree of weakness of the knee of hips develops by middle-age in over 50% of people.

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9. How severely affected would my sons and daughters be?

Evidence now suggests that within a family the severity tends to follow a similar trend. It is unusual to find brothers or sisters who are affected to very different degrees, and males and females tend to be affected equally. Unfortunately, it does seem that it would be very unusual for someone to be affected more mildly than their affected parent has been at the same age, and there is suggestion that there may tend to be increasing severity with each successive generation in a family (a phenomenom referred to as ‘clinical anticipation’).

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10. At what age does it normally start?

Signs of muscle weakness (particularly in the face) are evident by the age of 12 years in at least 50% of persons who carry the gene, and by the age of 20 years in 95%. Often an affected person first becomes aware of muscle weakness in childhood or teenage years when he or she experiences difficulty in raising one or both arms. Prominent shoulder blades are frequently another sign. Weakness of the legs can also develop during childhood. In other people symptoms may not be noticed until adulthood.

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11. How is it inherited?

Each hereditary characteristic or function is determined by a seperate gene. These genes are packed together into chromosomes like beads on a string. We have two copies of each chromosome (excepting the X and Y chromosomes in males), and therefore two copies of each gene. The gene for FSHD is now known to be on chromosome 4. In an affected person, one copy of this particular chromosome pair (i.e. the one passed from the affected parent, where inherited), carries a faulty FSHD gene. Hence there is an equal 50:50 chance for each of the offspring of an affected parent to inherit either the faulty copy (resulting in FSHD) or the good copy (resulting in no risk of being affected by FSHD for these individuals or their descendants).

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12. Is there always a family history?

Usually but not always. In 10-20% of all cases, a person diagnosed with FSHD has a fresh gene mutation (i.e. they have not inherited it from either of their parents). However, an isolated case cannot from history alone be assumed to be due to new mutation, since quite often a person newly diagnosed finds that there are other affected family members who had not been previously recognised owing to the signs or symptoms being very mild, or that they had been misdiagnosed. Also, even where neither parent of a ‘new mutation’ case has any clinical signs, they can still be at risk of having a further affected child. This applies where the mutation has arisen in cells in one parent prior to the cell divisions required for sperm of egg formation, making the parent a ‘mosaic’ for the mutation. In other exceptional cases, an understanding of whom may provide clues to eventual treatments, one parent appears to carry the mutation in full dose without showing any clinical sign or symptom of FSHD.

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13. Can FSHD now be diagnosed from a blood sample?

Yes, potentially in over 95% of cases, but this may require the blood sample to be very fresh in order to be able to use a particular technique for extraction of the DNA which ensures that long lengths of DNA can remain intact during the extraction process. For an apparently isolated case, a definitive diagnostic test requires a blood sample from both parents as well as from the affected person. In familial cases it is very helpful if blood is also available from other affected family members and from the unaffected parents.

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14. If I have no symptoms can I still carry the gene and pass it on to my children?

Since most people with FSHD show symptoms before the age of 20 years, it has been calculated that the son or daughter of an affected person who shows no features of the condition and is over 20 years of age has roughly only a 1 in 20 chance of carrying the gene. The risk is reassuringly lower than this for and adult brother or sister of someone who has been affected from childhood with a relatively severe presentation. However, the risk will be higher where affected family members have shown a relatively mild presentation with later-than-average onset. A proportion of people who are affected only mildly, are unaware of the abnormal signs that are present. Therefore, reassurance can only reliably be given to those ‘at risk’ following examination by a doctor familiar with the condition and combined with appropriate DNA testing from a blood sample.

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15. Can I avoid passing the faulty gene on to my children?

The ability to recognise in most cases the gene fault causing FSHD, allows geneticists to offer a DNA test on blood to determine whether a family member has or has not inherited the faulty gene, provided that a sample is also available from an affected family member. This can help resolve any uncertainty over the affected status of a young adult.

For a parent who has inherited the gene fault, it would also now be possible in most cases, where requested, to offer a test early in pregnancy (from chorion villus biopsy), usually at 11 weeks gestation, to determine whether the foetus has inherited FSHD or not. Eventually one can forsee it being possible in FSHD for a couple to commence a pregnancy by test tube fertilization, followed by genetic testing and subsequent re-implantation only of embryos which do not carry the faulty gene. This would avoid the difficult decision regarding termination of pregnancy which is currently the consideration for any couple who might choose a prenatal test. The use of donor sperm of eggs might be an alternative option for a couple seeking to avoid passing on the faulty gene. Family members or couples seeking further information should seek referral to their local clinical genetic service.

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16. How common is it?

Three seperate studies in Europe each indicate FSHD to be at least as frequent as 1 in 50,000 people. Allowing for those with mild presentation and for others in whom the diagnosis may remain unrecognised, the frequency in Britain is probably closer to 1 in 20,000 people (about 3,000 cases in all).

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17. 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 wasted muscles. If exercises are undertaken to increase muscle strength, build up should be done gradually.

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18. Can surgery help?

The scapular muscles which attach the shoulder blades to the chest are often very weak and this often leads to difficulty lifting the arms. The operation of scapular fixation (fixing the shoulder blades to the ribs at the back) has enabled some severely affected people to regain some 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.

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19. Are anaesthetics a risk?

There is no known risk, but you should be sure that the anaesthetist is aware of your diagnosis prior to the operation.

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20. 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 lifespan you should ask your doctor for a letter of support of you run into problems. When applying for a driving license, especially HGV or PSV, this may be issued for a limited duration, with renewal subject to satisfactory medical examination.

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21. Can any other problems be anticipated?

In a few people, including some of the more severe isolated cases with onset of symptom in early childhood, hearing loss and specific problems with the blood vessels at the back of the eye (retinal vessels) have been found. It is not yet clear whether these rare features are generally associated in mild degree with FSHD, or are limited to these few cases. Since the potential for leakage from retinal vessels can be minimised if laser treatment is given to the few who have this problem, it is advisable for people with FSHD to request an appropriate eye check every few years.

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22. Is the genetic fault known?

In all cases apart from one or two families worldwide, the gene fault causing FSHD is known to locate to the end of the long arm of chromosome 4 (region 4q35). In this region is a section of DNA where a sequence of 3300 bases (each base being an individual “letter” in the DNA code) is repeated multiple times. The DNA fault causing FSHD is the loss (deletion) of most of these repeat units. The remaining number of repeat units varies between different families but seems to stay constant within a family, and may be partly responsible for the degree of severity of the condition in any one person. The larger the deletion (i.e. the fewer repeats remaining) the earlier tends to be the onset and the greater the eventual severity of the condition.

The 3300 base repeat unit is not itself believed to be coding for a protein which is primarily at fault in the muscle, but rather the loss of these repeats might be altering the folding coils of DNA in that region of chromosome 4, and thereby affecting the normal expression of other genes in the region. The “true” FSHD gene whose protein product in muscle is disturbed, may be one or more of these.

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23. What are the current areas of research?

FSHD is a condition in which mutation is known, but not the gene itself. There are six principal lines of research:

1. The origin and mechanism of the mutation;
2. Factors controlling the variation in severity of the condition, and correlation of this with the mutation;
3. Further refinement of the specific diagnostic test;
4. An effort to characterise the gene(s) which is not working properly in muscle tissue;
5. Any potential current drug treatments which may even temporarily maintain muscle strength;
6. Following and documenting the natural history of the condition in a measurable form in order to provide a baseline against which the effiacy of future treatments can be evaluated.

All these lines of research will hopefully progress with the continuing collaboration between the researching doctors/scientists and individuals and families with FSHD in the many different countries involved.

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