Spectrum of the mitochondrial DNA mutations of Leber's hereditary optic neuropathy in Koreans

We investigated 14 primary mitochondrial DNA (mtDNA) mutations at nucleotide positions (nps) 3460A, 4160C, 5244A, 9101C, 9804A, 10663C, 11778A, 13730A, 14459A, 14482G, 14484C, 14495G, 14498T, and 14568T, and one common secondary mutation at np 15257A, in 82 Korean patients with suspected Leber's hereditary optic neuropathy (LHON). Only three kinds of LHON mutations were identified in 60 (73 %) of the 82 probands, these being the 11778A, 14484C, and 3460A mutations with 46 (56 %), 13 (16 %), and 1 (1 %) cases, respectively. None of the other mtDNA mutations was detected. Of the 60 probands with LHON positive mutations, 19 (32 %) had relevant family histories. Heteroplasmy was determined in 2 (4 %) of the 46 probands with the 11778A mutation and 1 (8 %) of the 13 probands with the 14484C mutation. In conclusion, the 11778A mutation was the most common cause (56 %), with a high prevalence of the 14484C and a lower prevalence of the 3460A mutations being characteristic of Korean patients with LHON. The 3460A mutation especially showed a remarkable racial difference from that in Caucasians. With the exceptions of the 3460A, 11778A, and 14484C, the mutations screened may not be involved in the pathogenesis of LHON in Koreans and may not have a synergistic effect on its clinical expression.