GeneReviews Updates FMR1 Disorder Guidelines
Hunter and colleagues at the University of Washington have revised the GeneReviews clinical guidance for FMR1 disorders. The three conditions covered are fragile X syndrome, fragile X-associated tremor/ataxia syndrome (FXTAS), and fragile X-associated primary ovarian insufficiency (FXPOI). Diagnosis relies on molecular testing to detect CGG trinucleotide repeat expansion in FMR1. Males with full mutations (over 200 CGG repeats) develop fragile X syndrome, which causes developmental delay and intellectual disability. Between 50% and 70% of those affected also have autism spectrum disorder. The review details characteristic craniofacial features that become more obvious with age, plus medical problems including hypotonia, gastroesophageal reflux, strabismus, seizures, and sleep disorders. FXTAS typically begins between ages 60 and 65, affecting 40% of males with a premutation and 16% to 20% of females. FXPOI occurs in 20% of women carrying a premutation allele, compared to 1% in the general population.
The updated guidelines provide standardized diagnostic criteria and management protocols for FMR1 disorders that affect thousands of families worldwide.
Written by the Genomes desk from the primary source linked above and checked against it. Research use only; not medical advice. Corrections: [email protected].