A Novel NDUFS3 mutation in a Chinese patient with severe Leigh syndrome.

Leigh syndrome is one of the most common subtypes of mitochondrial disease. Mutations in encoding genes of oxidative phosphorylation complexes have been frequently reported, of which, MTATP6 was one of the most frequently reported genes for Leigh syndrome. In this study, by using next-generation sequencing targeted to MitoExome in a patient with clinical manifestations of Leigh syndrome, two missense mutations of NDUFS3 (c.418 C > T/p.R140W and c.595 C > T/p.R199W) were identified, of which c.418 C > T was novel. Functionally, the patient derived lymphoblastoid cells showed decreased amount of NDUFS3 and complex I assembly when compared with two control cells. Although NDUFS3 mutations have been related to late onset Leigh syndrome, we found that the patient carrying these two mutations developed an early onset Leigh syndrome. To our knowledge, this is the second study on patient carrying NDUFS3 mutations. In conclusion, we identified a novel Leigh syndrome causing NDUFS3 mutation and expanded the clinical spectrum caused by NDUFS3 mutations in this study.