GPs urged to test for genetic condition affecting one in 250 women

The syndrome is caused by an alteration to a gene on the X chromosome

Alex McQuade with sons Evan (left) and Xander (right), who have Fragile X syndrome (Family Handout/PA Wire)

GPs have been urged to test patients for a genetic condition that is the most common inherited cause of learning disability.

There is a “surprising lack of awareness” around Fragile X, experts said.

About one in 250 women and one in 600 men are carriers of the abnormal gene that causes Fragile X, with female carriers at a higher risk of early menopause.

The syndrome is caused by an alteration to a gene on the X chromosome, which disrupts the production of a protein needed for brain development.

Women with the gene have a 50% chance of passing on the condition to their children, while an affected man will pass the condition on to daughters, but not sons.

Fragile X syndrome affects about one in 4,000 males and one in 6,000 females, causing a range of developmental issues.

Pete Richardson, managing director of the Fragile X Society, 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.”

People are more likely to be carriers if they have a family history of Fragile X syndrome – or of intellectual disability, developmental delay or autism of unknown cause – as well as infertility problems associated with elevated follicle-stimulating hormone levels or premature ovarian failure.

Women with ovarian insufficiency also have a 2-15% chance of being a Fragile X carrier.

Mr Richardson 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.”

Alex McQuade with sons Evan (left) and Xander (right), who have Fragile X syndrome (Family Handout/PA Wire)

According to the Fragile X Society, patients who suspect they may carry the gene can ask medical professionals for a Fragile X (FMR1) DNA test.

Alex McQuade, 41, raised concerns when her baby missed his developmental milestones.

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 couple, from Groby, Leicestershire, thought the issues experienced by their son, Evan, now 10, were a one-off.

However, their second child Xander, now seven, had similar problems.

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.”