Curation FXTAS,POF1 FMR1

Study evaluated 93 male FMR1 premutation carriers (60-133 CGG repeats) with documented action tremor and/or gait ataxia; onset ages were obtained by history and carrier status was confirmed by PCR and Southern blot.

In 93 male premutation carriers, larger FMR1 CGG repeat size correlated with earlier onset of tremor (P=0.001), ataxia (P=0.002), and either core motor symptom (P<0.0001).

FXPOI risk is dependent on the number of CGG repeats.

In a cohort study of 110 daughters of men with FXTAS, compared with 43 non‑carrier female controls and 36 premutation carrier daughters of parents without FXTAS, daughters of men with FXTAS had a significantly higher prevalence of neurological, psychiatric, and menopausal symptoms. Balance and menopausal symptoms were reported as significantly increased relative to both comparison groups.

FMR1 mRNA was quantified from peripheral blood leukocytes in premutation carriers and controls; leukocyte mRNA levels did not correlate with motor rating scores, so regulatory support from this study is indirect and locus/gene-level.

A CGG‑repeat knock‑in mouse model (100 CGG repeats in Fmr1) shows elevated Fmr1 mRNA, normal FMRP levels, and progressive neuronal intranuclear inclusions that increase in size and number with age. Inclusion burden correlates with tremor/ataxia phenotypes in humans, supporting a direct role of CGG expansion or RNA toxicity in FXTAS pathogenesis.