Purpose: To define the prevalence of a panel of mitochondrial DNA (mtDNA) mutations associated with Leber's hereditary optic neuropathy (LHON) in the Turkish LHON population. LHON-associated mtDNA mutations have been found in LHON patients from around the world, but the Turkish LHON population has not been studied.
Methods: Thirty-two Turkish patients were defined clinically as having LHON on the basis of painless, subacute, bilateral optic neuropathy and the exclusion of other causes of subacute optic neuropathy. mtDNA was extracted from blood of the 32 probands and assayed for a panel of primary and secondary LHON-associated mtDNA mutations by polymerase chain reaction (PCR)-based methods. We studied three well-known LHON-associated primary mutations (at nucleotide positions 11778, 3460 and 14484) and one common secondary mutation (at nucleotide 15257) in all 32 probands. In addition to these mutations, 18 of the 32 probands were tested for the Complex IV, COX III gene, LHON associated 9804 and 9438 mutations and secondary LHON mutations at nucleotide positions 3394, 4160, 4216, 4917, 5244, 7444, 7706, 13708, 13730 and 15812.
Results: Among the 32 probands tested for four common LHON mutations, 3 carried the 14484 mutation, 1 carried the 11778 mutation, 1 carried the 3460 mutation and 1 carried the 15257 mutation. Among the 18 LHON patients who tested for additional mutations, 1 proband harboured the 9804 mutation and 4 carried the secondary mutations at nucleotide positions 4216, 4917 and 13708.
Conclusion: The results of mtDNA analysis of the Turkish LHON patients appear to be different from those of previous reports.