Fragile X syndrome is the most common cause of severe learning disability after Down’s syndrome. Intellectual impairment is severe, girls can be normal but a large proportion are impaired.
Fragile X is a family of genetic conditions, which can impact individuals and families in various ways. These genetic conditions are related in that they are all caused by gene changes in the same gene, known as the FMR1 gene.
Fragile X syndrome (FXS) is the most common cause of inherited mental impairment. This impairment can range from learning disabilities to more severe cognitive or intellectual disabilities. FXS is the most common known cause of “autistic-like” behaviour. Symptoms also can include characteristic physical and behavioural features and delays in speech and language development.
Fragile X syndrome females can experience problems with ovarian function which can lead to infertility and early menopause. Female gene carriers can also have these ovarian function problems.
Some gene carriers do not exhibit any of these features.
Fragile X can be passed on in a family by individuals who have no apparent signs of this genetic condition. In some families a number of family members appear to be affected, whereas in other families a newly diagnosed individual may be the first family member to exhibit symptoms.
Only mothers need to be tested with the Fragile X syndrome (FXS) Genetic Screening Test.