Doctors urged to start testing for 'Fragile X' syndrome affecting one in every 250 women

Fragile X syndrome disrupts the production of a protein needed for our brain development - and is triggered by an abnormal gene found in roughly one in 250 women

GP's across the country are being urged to test patients for Fragile X syndrome - the most common inherited cause of learning disability - with around one in 250 women carrying the abnormal gene.

Fragile X syndrome is caused by a genetic mutation that disrupts brain development, which is found in roughly one in 250 women, and one in 600 men. Female carriers are at higher risk of early menopause, and have a 50% chance of passing the condition to their children. Men with the condition will pass it on to their daughters, but not their sons.

The condition affects approximately one in 4,000 males and one in 6,000 females, leading to various developmental issues, Wales Online reports. A charity has called on increased testing amid concerns of a "surprising lack of awareness" about the condition.

Pete Richardson, managing director of the Fragile X Society, says carriers often don't know they're affected. He said: "As the most common inherited cause of learning disability, there is a surprising lack of awareness around Fragile X syndrome. Carriers of the Fragile X pre-mutation often won't know they are affected."

Those with a family history of Fragile X syndrome, intellectual disability, developmental delay, or autism of an unknown cause, as well as infertility problems, are more likely to be carriers. Women who experience early signs of menopause need to be aware they might be carriers of Fragile X, a condition often overlooked by doctors, said Mr Richardson. He added: "When a woman shows signs of premature menopause, being a Fragile X carrier is often the last thing that doctors will investigate. We need this to change. Now."

For those worried they may have inherited the gene, the Fragile X Society advises seeking out a Fragile X (FMR1) DNA test. Alex McQuade, a 41-year-old mother, became concerned when her son didn't hit his expected developmental stages. Reflecting on her experience, she said: "At no point was there a conversation about genetics, despite myself and husband Chris telling doctors that I had a female cousin with what I thought was an autistic son."

The McQuades, from Groby, Leicestershire, assumed their eldest child's struggles were an anomaly - until their second son started showing similar symptoms. Mrs McQuade said: "I began doing my own research online. I knew it was like autism, but autism didn't quite fit. It wasn't long before I came across Fragile X syndrome. When I found the list of physical symptoms there was no doubt in my mind that the boys had it."

What is Fragile X syndrome and how do you know if you carry it?

What is Fragile X syndrome?

Fragile X Syndrome is the number one genetic cause of learning disabilities, impacting around one in every 4,000 boys and one in 6,000 girls, Mr Richardson says. "It can cause a wide range of difficulties with learning, as well as social, language, attentional, emotional and behavioural problems.

"The mutation that causes FXS can grow larger when passed on to the next generation, so people with FXS may not have a family history. Also, both girls and boys can have FXS. However, females often have a milder presentation of the syndrome's features."

What causes it?

Mr Richardson says the condition is cauaed by the presence of an abnormal gene. He says: "Fragile X syndrome is caused by a change in the FMR1 gene, and the FMR1 gene is located on the X chromosome.

"This abnormal gene, which can be passed from generation to generation, is usually inherited through the gene that is carried by women. Although both males and females can be FMR1 carriers, and can pass the premutation on to their offspring."

What are the symptoms?

Fragile X syndrome manifests in a variety of physical, mental and behavioural symptoms, ranging from mild to severe intellectual disability. Richardson says: "Common behavioural features include short attention span, distractibility, impulsiveness, restlessness, over activity and sensory problems. Learning disabilities occur in almost all males with Fragile X, to differing degrees."

However, some females with the condition can appear less affected, "because females have two X chromosomes, and usually only one of them is affected by Fragile X, the impact of the condition varies. Some females appear unaffected, others have a mild learning disability, and some have a more severe learning disability."

"Girls with or without learning disabilities may show concentration problems and social, emotional and communication difficulties related to extreme shyness and anxiety in social situations."

Physical features associated with Fragile X are often not very obvious in young children, Richardson says, adding: "Physical features include a long face, large or prominent ears, and flat feet which usually become more noticeable in young adults than in children and in males more than females. Males with the condition may also have enlarged testes."

Are carriers of Fragile X at risk of any health problems?

Women carriers often experience early menopause. "Fragile X-Associated Primary Ovarian Insufficiency (FXPOI) is a condition that can affect carrier women under the age of 40," Richardson points out. "Symptoms include decreased or abnormal ovarian function, which can lead to infertility or fertility problems, irregular or absent periods, or premature ovarian failure."

"When a woman shows signs of premature menopause, being a Fragile X carrier is often the last thing that doctors will investigate. We need this to change."

How is it diagnosed?

Finding out if someone has the condition can only be done via a DNA test.

"This process is easier if there is an identified carrier already in the family, or someone with Fragile X syndrome and can be arranged by a GP/family doctor, or any physician or genetic counsellor," Richardson said.

How is it managed/treated?

Richardson stresses that although there isn't a cure for the condition, there are treatments available to help alleviate its symptoms.

"Individuals with Fragile X who receive appropriate education, therapy services, and medications have the best chance of using all of their individual capabilities and skills", he said. "Even those with an intellectual or developmental disability can learn to master many self-help skills."

Early intervention is also very important, Richardson adds. This is because a young child's brain is still forming, and so "early intervention gives children the best start possible and the greatest chance of developing a full range of skills."

"The sooner a child with Fragile X syndrome gets treatment, the more opportunity there is for learning."