The prevalence of fragile X syndrome differs between males (1 in 4000) and females (1 in 8000).
Fragile X syndrome arises from a genetic mutation in a gene on the X chromosome.
80% of individuals with fragile X syndrome will have one or more of the physical features of the syndrome, but the presence of these features varies with age and sex.
Children with fragile X syndrome have relative strengths in vocabulary capacity, processing of simultaneous information, and long-term memory.
Difficulties are seen in verbal short-term memory, sequential processing of information, and executive functioning.
Females with fragile X syndrome have a unique profile of strengths and weaknesses.
The link between fragile X syndrome and Autism Spectrum Disorder (ASD) is complex. Estimates of ASD range from 21-80%.
Individuals with fragile X syndrome often show repetitive behaviour.
Some males with fragile X syndrome may only experience mild difficulties with language and communication, whereas others may not develop any spoken language.
Social anxiety is very common in fragile X syndrome, with approximately 75% of males displaying excessive shyness and anxiety.
Around half of all individuals with fragile X syndrome have clinically significant sleep difficulties.
It is estimated that many individuals with fragile X syndrome show impulsive and overactive behaviour.
The Fragile X Society is a UK based charity that provides support to families and individuals with fragile X syndrome.