This is a retrospective, multicenter international study comprising multiple centers in France and Belgium, to evaluate the clinical features of late-onset FA (onset after age 25 years) and very late-onset FA (onset after age 40 years). The authors find that delayed-onset Friedreich's ataxia (late-onset Friedreich's ataxia and very-late-onset Friedreich's ataxia) had less frequently dysarthria, abolished tendon reflexes, extensor plantar reflexes, weakness, amyotrophy, ganglionopathy, cerebellar atrophy, scoliosis, and cardiomyopathy than typical-onset Friedreich's ataxia, along with less severe functional disability and shorter GAA expansion on the smaller allele (P < 0.001). Delayed-onset Friedreich's ataxia had lower scale for the assessment and rating of ataxia and spinocerebellar degeneration functional scores and longer disease duration before wheelchair confinement.

Read more: Delayed-onset Friedreich's ataxia revisited