Adult-onset ataxia and polyneuropathy caused by mitochondrial 8993T arrow right C mutation

The 8993T arrow right C mutation in mitochondrial DNA (mtDNA) has been described previously to be associated with infantile-or childhood-onset phenotypes, ranging from Leigh's syndrome to neurogenic weakness, ataxia, and retinitis pigmentosa syndrome. We report a kindred with adult-onset slowly progressive ataxia and polyneuropathy and with the heteroplasmic 8993T arrow right C mutation. Our findings suggest that the 8993T arrow right C mtDNA mutation should be considered in the differential diagnosis of nondominant adult-onset ataxia and axonal neuropathy. Ann Neurol 2005; 58:337-340