“I thought he was dyslexic. It was a primary teacher who spotted what was really wrong with him. She’d come across a pupil with Williams Syndrome before, and once seen it’s never forgotten,” says Susie Morgan, mother of 10-year-old Guy.

Having struggled through his first two years at primary school, Guy Morgan was diagnosed with Williams Syndrome - a little- known condition which affects children’s ability to learn, and which is now the subject of a video for teachers.

Guy was lucky. Many children spend several years in mainstream schools before their disability, named after the New Zealand doctor who discovered it in the 1960s, is spotted.

Susie Morgan, who is now education co-ordinator of the Williams Foundation, a support group for families, says: “It’s often assumed affected children are just slow or lazy. They get left behind and become unhappy and disruptive. ”

Williams Syndrome is a genetic condition caused by a missing chromosome and is thought to occur in around 1 in 10,000 children. Children with Williams lack concentration, have no analytical skills and have difficulty reading and writing. Most cannot cope with mainstream education and need special care.

All Williams children have similar physical characteristics which include elfin-like features, weak eyes and muscles, stunted growth, poor coordination, dislike of loud noise and a constant need to pass urine. Perhaps more difficult to spot is an almost “telepathic” empathy and a need for constant communication.

Susie Morgan says: “The gregarious personality is another reason why they can get overlooked. Teachers can assume they have a overly friendly child who would rather talk than concentrate. That isn’t the case. The constant talking is a need for reassurance. For example, Guy is worried by weather and chatters incessantly when he feels a storm brewing. The funny thing is he can always predict them.”

Sadly, the Williams child’s out-going personality doesn’t help them make friends.

“They only seem to connect with adults and without exception find it almost impossible to join peer groups. Their physical impairments mean sport and playground games cause them great problems, which can lead to teasing from other children,” says Mrs Morgan.

Dr Tassos Stevens has just completed a three-year study into Williams Syndrome, sponsored by the Medical Research Council. He also produced the video for schools.

“There are hundreds of childhood syndromes and it’s impossible to expect teachers to be expert at spotting them all. We wouldn’t expect that from a GP,” says Dr Stevens.

However, he does believe teachers can help, especially if they know they have a Williams child in the classroom. He says: “Lots of activities to use up their hyper-energy together with shorter periods of academic teaching would be perfect for Williams children. Also, it’s important not to forget that just because Williams children have great verbal skills, often ahead of their age group, they really do struggle with the practicalities of learning.”

Dr Stevens knows that most teachers could not possibly hope to offer a Williams child in their class enough individual attention. However, he believes there are simple measures which would make life easier without disrupting the rest of the class. “If possible reduce class noise, try to sit them away from noisy windows, don’t chastise them for the constant toilet trips and keep an eye out for bullies.

“But the most important things of all are encouragement and confidence-building. I met one girl who hated school because her teacher chastised her for messy handwriting. Williams children don’t possess fine motor control which everyone needs for delicate tasks like writing, so it was inevitably messy. Many of these children are intelligent enough to know they are different. Feelings of failure and depression are common. If a teacher could help them integrate in a classroom, it would go a long way to helping them cope with society.”

For more information on the Williams Foundation guidelines and video, write to: WSF, The Little Ruin, Edge Road, Edge, Stroud GL6 6NE. Telfax: 01452 812277.