Leber's hereditary optic neuropathy - The spectrum of mitochondrial DNA mutations in Chinese patients

Purpose: To investigate the spectrum of mitochondrial DNA (mtDNA) mutations in Chinese patients with Leber's hereditary optic neuropathy (LHON), optic atrophy of unknown etiology, and optic neuropathy of known etiology. Methods: Twenty-seven patients from 25 LHON pedigrees, 22 patients with bilateral optic atrophy of unknown etiology, 21 patients with optic neuropathy of known etiology, and 25 normal healthy controls were included in this study. Twelve pairs of primers that covered the 21 reported mtDNA mutations were utilized. Single-strand conformation polymorphism analysis and DNA sequencing were used to detect base substitutions in mtDNA. Results: Twenty-three LHON pedigrees (92%) had the 11778 mtDNA primary mutation. Two pedigrees (8%) had the 14484 mutation. No 3460 mutations were detected in this group. Thirteen other sequence changes were found in these patients, but only the 4216 mutation had been reported previously. Thirteen pedigrees had multi-mutation patterns consisting of one primary mutation together with other sequence changes. No primary mutations were found in patients with optic atrophy of unknown etiology or in patients with optic neuropathy of known etiology. Conclusions: High frequency of 11778 mtDNA mutation was found in Chinese patients with LHON. No specific multi-mutation pattern such as the European mtDNA haplogroup J was found.