They are called "orphan diseases": disorders so rare that no researcher or drug company will dedicate time and money to looking for a treatment or cure. Yet taken together, the number of children with one of the 5,000-plus rare syndromes may reach tens of thousands, a bigger group than some far better-known conditions.
Around 1,200 babies are born annually in the United Kingdom with a rare syndrome. This is defined as one that affects five or fewer people per 10,000. More than 150,000 schoolchildren live with one. Many who would have died now survive, and many are diagnosed much earlier, thanks to intensive neonatal care and medical genetics.
Yet for schools, the essential fact remains: given a child diagnosed with anything from Aarskog syndrome to Zellweger syndrome, most teachers know they have almost certainly never encountered a child like this before, and, almost certainly, they never will again.
Information and planning
"It was absolutely terrifying when we heard we had a child coming with severe brittle bone disease," recalls Pat Harwood, learning mentor at Range high school, an 11-18 mainstream Merseyside comprehensive. Range has a single-storey building, an onsite nurse and expertise with physically disabled students. But they had never had to plan like this before.
"We had a whole-school assembly, so everyone knew they must give her space in the corridors. They mustn't walk behind her in case she stopped her wheelchair and they bumped into her. Her class had to remember not to pass anything over her head. We thought it would be a nightmare. But, after a couple of years, everyone adapted.
"She left us for university and recently she died there. But while she was here we took her on the Kielder Challenge (an adventure competition for 13 to 16-year-olds, with and without disabilities). It was wonderful: she loved to be out in the cold and the rain because she so rarely was. All the time you were thinking would she pull on a rope and break a finger. But she just got wet and laughed."
For schools to understand the needs of such unusual children, they must seek detailed information in advance, says Diane Barnett, information officer of the charity Contact a Family. No one could possibly expect them to know anything about syndromes they have not heard of. The internet will give some information, but it comes with a health warning.
"It's really important to test the quality of the information, because it's so variable," says Ms Barnett. "Anything you use should give details of the expert who wrote it, when it was last updated, and, if it recommends medication, whether it was sponsored by a drug company."
Seeing a spectrum
While most support groups publish medical information, few have the resources for education expertise. (The Fragile X Society, the Prader-Willi Syndrome Association, and the Turner Syndrome Support Society are among those who offer consultancy, publications or telephone advice for teachers.) But the over-riding and slightly paradoxical principles frequently repeated by these and similar groups are that, when trying to understand and plan for the needs of these children, schools must acquaint themselves with the full extent of the child's potential symptoms, but not assume that the child will show all of them. The model of autism, now widely known in schools, where each child is seen as being on a spectrum, is a good starting point, says Diane Barnett. Some websites show worst-case scenarios, yet not every child will have every feature of a disorder, and their severity will vary. Teachers need to know what to look for, but not always expect to see it. It sounds simple, she adds. It becomes difficult because of the extraordinary nature of some of these children's symptoms.
Some learning patterns appear to be common among many children with genetic diseases: rigidity of thought, the need for concrete rather than abstract language, poor short-term memory and attention skills. Other issues have wider implications: children's sexual development may be affected by chromosomal abnormality; girls may be infertile, although IVF treatment holds out some hope; boys may be sterile or inappropriately sexually active, while those with degenerative diseases need individual pastoral support and whole-school sensitivity. The most difficult are where symptoms are not only rare but seem inexplicable, or attract more common, but unfortunately incorrect explanations.
Consultant paediatricians have told Contact a Family about a school that insisted a 17-year-old could not possibly suffer from dementia, despite it being an established symptom of her diagnosed Niemann-Pick syndrome type C; of a child's over-friendly behaviour (William's syndrome) or self-harm (Lesch-Nyhan syndrome) that were interpreted by schools as evidence of abuse.
"With the best will in the world, it's hard for teachers to understand, when faced with a child who has bitten its lips and cuts its arms, that this is not a child-protection issue," says Diane Barnett.
But, adds Jacqueline Wood, regional co-ordinator of the Prader-Willi Syndrome Association, it can be a matter of life and death. "Our children will eat all the time, because their appetite-control mechanism doesn't work. If they're not watched and prevented, they die from obesity-related conditions in their twenties.
"If a teacher or another child puts a half-eaten sandwich in the bin, our children will take it out and eat it. They shouldn't be told off for that: it's beyond their control. Staff struggle to get their heads round this.
They think 'Poor little thing - she's hungry.' But it's the food that kills them."
Contact a Family Helpline 0808 8083555; www.cafamily.org.uk has online database of 400 rare syndromes, and offers telephone advice on more than 1,000. It advises on assessing information and gives links to websites of many small support groups American National Organisation for Rare Disorders www.rarediseases.org
Unique: the Rare Chromosome Disorder Support Group www.rarechromo.org
Syndrome Without a Name A new support group for children who never receive a diagnosis. Tel 01922 701234; www.undiagnosed.org.uk