Phenotypic Heterogeneity in Patients with Mutations in the Mitochondrial Complex I Assembly Gene NDUFAF5

Background Rare mutations in NADH:ubiquinone oxidoreductase complex assembly factor 5 (NDUFAF5) are linked to Leigh syndrome. Objective We aimed to describe clinical characteristics and functional findings in a patient cohort with NDUFAF5 mutations. Methods Patients with biallelic NDUFAF5 mutations were recruited from multi‐centers in Taiwan. Clinical, laboratory, radiological, and follow‐up features were recorded and mitochondrial assays were performed in patients' skin fibroblasts. Results Nine patients from seven unrelated pedigrees were enrolled, eight homozygous for c.836 T > G (p.Met279Arg) in NDUFAF5 and one compound heterozygous for p.Met279Arg. Onset age had a bimodal distribution. The early‐onset group (age