Delineating the pathogenic threshold and phenotypic spectrum of SCA27B: findings from a large French-Canadian cohort.

ABSTRACT:

Background

Autosomal dominant spinocerebellar ataxia 27B (SCA27B), caused by an intronic (GAA•TTC) repeat expansion in FGF14, is a common cause of late-onset cerebellar ataxia, but its genotypic and phenotypic spectrum remains to be fully established.

Methods

We analysed the FGF14 (GAA•TTC) repeat expansion in a cohort of 134 patients with ataxia and 822 controls from Quebec. We conducted segregation study in large families to further characterize intergenerational repeat instability.

Results

We found a significant enrichment of (GAA•TTC)_≥200 alleles in the ataxia cohort compared to controls (53.0%, 71/134, vs 3.6%, 30/822, p < 0.0001), including for (GAA•TTC)_200-249 alleles (8.2% vs 2.6%, p = 0.0026). We identified 12 ataxic patients with a phen

SUBMITTER: Iruzubieta P 

PROVIDER: S-EPMC12450228 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature