Fragile X Premutation

Fragile X premutation carriers harbor FMR1 allele expansions containing fifty-five to two hundred CGG repeats, predisposing them to distinct clinical syndromes driven by elevated toxic messenger ribonucleic acid levels. Adult carriers face risks of fragile X-associated tremor ataxia syndrome presenting with progressive cerebellar ataxia and intention tremor, alongside fragile X-associated primary ovarian insufficiency in women. Clinical management requires genetic counseling, family screening, and targeted neurological and endocrine surveillance.