Large-Scale Whole Genome Sequence Analysis of >22,000 Subjects Provides no Evidence of Premutation Allele Involvement in Autism Spectrum Disorder.

Expansion of a CGG repeat in the Fragile X Messenger Ribonucleoprotein 1 ( gene on the X chromosome is the cause of Fragile X Syndrome (FXS). The repeat length of unaffected individuals varies between 5-40 repeats, whereas >200 repeats are observed in cases of FXS. The intermediate range between 55-200 repeats is considered the premutation range and is observed in roughly 1:300 females and 1:900 males in the general population.