A genetic disorder that causes learning disabilities is sadly still under-diagnosed. Maggie Jones uncovers Fragile X
Fragile X syndrome is the commonest inherited cause of learning disability. One in 4,000 males and one in 8,000 females has the condition. The syndrome was first recognised around 30 years ago and it seems astonishing that it is still so under-recognised.
Unusual gene Fragile X is caused by an unusual gene on the X chromosome which prevents the production of a particular protein in the body. No-one is quite sure what this protein does, though it is clearly important for the development of normal learning and behaviour. Because it is carried on the X chromosome, boys who inherit the gene are normally more severely affected than girls.
Fragile X can be carried as a pre-mutation which has few effects, but if the gene changes to the full mutation, the child is likely to suffer from a range of symptoms which include general developmental delay, speech problems, difficulties in concentrating and some autistic behaviours too.
Dr Jeremy Turk, a senior lecturer in Child and Adult Psychiatry at St George's Hospital Medical School who has a special interest in Fragile X, believes there are substantial numbers of children with Fragile X who have not been diagnosed.
'There are a number of reasons why this is the case,' he explains. 'First, the syndrome does not have such obvious physical characteristics as Down's syndrome, and the facial features are quite subtle. Second, it is very variable - some children will have quite severe learning difficulties, while others may be of lower average intelligence.
' Dr Turk says the lack of diagnosis can be difficult for parents. 'The behavioural problems are often misconstrued as bad parenting, and this can cause a great deal of heartache. Also, once you do have a diagnosis you can put in place a whole package of intervention and support - sometimes including medication such as Ritalin - to enable the child to take part in essential social and educational activities.
' Case history Joe's story is typical of families who have a child with Fragile X. His mother Alex says, 'We noticed that Joe's development seemed to be behind other babies his age - he didn't sit up till he was one, or walk till he was two; he had no speech at all till he was three-and-a-half, and he was also very slow to be potty-trained.
'We saw a number of paediatricians - the response varied from one telling us that there was nothing wrong with him and that if we waited he would catch up, to another who said that he though Joe was autistic. This was a terrible blow and it took us a long time to get over it.
'Joe went to a mainstream nursery at three-and-a-half - this was a small, private nursery which suited him well. The staff had no special needs training but were incredibly helpful and supportive, and we think being with his peers really helped. Joe was held back a year before it was felt he was ready to enter mainstream school.
'But all was clearly not well, and finally a paediatrician suggested Fragile X. We had never heard of it. They did a blood test and when the result came back positive we were both shattered. It was not just the gloomy prognosis for Joe - they said he would be unlikely ever to lead an independent life - but also the fact that we had a high chance of another child being affected. Carrying a genetic disorder really took some coming to terms with.
'However, in some ways we feel lucky. We have had an incredible nanny who has provided both continuity and high quality care for Joe. And at least we know what it is before we have had another child - we know too many families who were diagnosed late so that they have more than one child with the syndrome.
'Joe is presently in a mainstream primary school, but he will start at a special needs school in September. He has very poor concentration, and the distractions in a class of 30 pupils are too great for Joe to deal with. We also feel he could really benefit from specialist teachers.
'We did try medication but it didn't work. We have also tried some alternative therapies and put a lot of effort into seeing that Joe went to music groups, baby gyms and all the usual activities which helped him overcome his fear of this type of environment. We do feel that integrating him with his non-special needs peers is valuable, especially as he is very imitative.'
The Fragile X Society produces an excellent video, 'Fragile X Syndrome', which costs 5 (inc p&p)
Recognising Fragile X
- Head may be large or long
- Ears may stick out
- Often overactive, restless, and impulsive
- May be shy, anxious or self-absorbed
- Reacts to busy, noisy or crowded environments
- Tends to carry out repetitive actions such as hand flapping and hand biting at times of distress or anxiety
- Dislikes eye contact
- Likes routine, finds change difficult to cope with