Analysis of the entire mitochondrial genome reveals Leber's hereditary optic neuropathy mitochondrial DNA mutations in an Arab cohort with multiple sclerosis.

Several mitochondrial DNA (mtDNA) mutations of Leber's hereditary optic neuropathy (LHON) have been reported in patients with multiple sclerosis (MS) from different ethnicities. To further study the involvement of LHON mtDNA mutations in MS in the Arab population, we analyzed sequencing data of the entire mitochondrial genome from 47 unrelated Saudi individuals, 23 patients with relapse-remitting MS (RRMS) and 24 healthy controls. Ten LHON mutations/variants were detected in the patients but were absent in the controls. Of them, the common primary pathogenic mutation m.14484T>C and the rare mutation m.10237T>C were found in one patient, whereas the rare mutation m.9101T>C was found in another patient. The remaining were secondary single nucleotide variants (SNVs) found either in synergy with the primary/rare mutations or individually in other patients. Patients carrying LHON variants also exhibited distinct mtDNA variants throughout the mitochondrial genome, eight were previously reported in patients with LHON. Moreover, five other LHON-related SNVs differed significantly in their prevalence among patients and controls (P < 0.05). This study, the first to investigate LHON mtDNA mutations/variants in a Saudi cohort may suggest a role of these mutations/variants in the pathogenesis or genetic predisposition to MS, a possibility which needs to be explored further in a large-scale.