Mutations in FMR1, the gene encoding fragile X messenger ribonucleoprotein 1 (FMRP), located at Xq27.3 and discovered in 1991, are the leading single-gene causes of autism and intellectual disability.

LAWRENCE, KANSAS — The most common inherited cause of intellectual disability, fragile X syndrome, is caused by mutations in a single gene, the FMR1 gene. FMR1 mutations occur when parents possess a ...