[Familial occurrence of FXTAS caused by premutation in the FMR1 gene]. / Rodzinne wystepowanie zespolu FXTAS powodowanego premutacja w genie FMRI.

ABSTRACT

The FMR1 gene premutation has recently been reported to be associated with a neurodegenerative syndrome, characterized by intention tremor, gait ataxia and cognition deficits in persons older than 50 years. We present a 74-year-old man with very severe intention tremor, slight postural tremor and gait ataxia. The molecular analysis revealed that he was a carrier of 91 CGG repeats in the FMR1 gene. His sister (68 years old), with head tremor, was found to be a carrier of 81 CGG repeats, while his younger brother, also with slight head and postural tremor, was a carrier of 98 CGG repeats. Molecular analysis of the proband's asymptomatic daughter revealed an expansion over 120 CGG. Her daughter, with mild intellectual disability, was a carrier of a full mutation. Thus, in the presented family with heterogeneous clinical presentation we found 4 premutations and one full mutation in the FMR1 gene.