Jeremy Turk, president of the Learning Disability Forum, said in Dundee today that many women at risk may not have an obvious family history of learning disabilities due to the nature of the inheritance. He warned that early diagnosis of the condition was critical as many parents often don’t realise their child has the syndrome until they reach school age, when they start falling behind.

Mr Turk was speaking to delegates at the Royal Society of Medicine’s Forum on Learning Disability, which is being held for the first time in Scotland, at Dundee’s West Park Conference Centre.

Fragile X is the most common cause of inherited learning disability and affects about one in 4,000 boys and one in 8,000 girls. Those with Fragile X syndrome tend to have learning and behavioural problems and as they get older they generally have largish heads and prominent ears.

Although these facial characteristics can become more pronounced with age, they can be quite difficult to spot in babies.

“Fragile X syndrome also leads to a range of behavioural and developmental problems and yet many people with the condition aren’t diagnosed and so can’t get the help they need,” said Mr Turk.

“The main problem is the degree of intellectual disability is very variable. The individuals look very normal and people don’t think of the fact that there may be an underlying genetic condition, so for a number of critical reasons that’s missed and they don’t get the genetic counselling they need.

“Individuals don’t get the early institution of a proper programme to help them, so they then end up having more problems than are necessary in a number of ways. They can miss out on the appropriate special education in terms of benefits.”

Mr Turk said people with Fragile X syndrome can develop intellectual disabilities, speech and language problems, autistic features, poor concentration and can be hyperactive.

“Even when a child is born with Fragile X syndrome, they can be very normal, unlike a condition like Down’s Syndrome where the appearance, often, is very characteristic,” he said.

“With these children, they look very normal, the age at which they smile, walk and even say their first words can be very, very normal, so unless there’s a family history, which isn’t necessarily the case, then it can be missed, and often doesn’t appear until school age where people realise the child isn’t keeping up with the rest of the class or behaving in a strange or different way.

“It’s crucial to have early diagnosis and early ascertainment of the problem and then the ability to put in place an appropriate remedial programme as soon as possible for the child’s development. It’s getting in really early to change a lifetime.

“As many as about one in 700 carry the potential to have a child with it, it is very common. Those 700 have a 50/50 chance of passing on the Fragile X gene.