Coenzyme Q10 deficiency due to a COQ4 gene defect causes childhood-onset spinocerebellar ataxia and stroke-like episodes

Primary coenzyme Q10 deficiency-7 is caused by homozygous or compound heterozygous mutations in the COQ4 gene. Until now 12 patients have been reported, most presenting with a lethal infantile phenotype with encephalopathy, epilepsy and cardiomyopathy. We report on a new phenotype of COQ4 deficiency: a childhood onset spinocerebellar ataxia with stroke-like episodes.