Leber's hereditary optic neuropathy: the spectrum of mitochondrial DNA mutations in Iranian patients.

We studied 14 patients with Leber's hereditary optic neuropathy (LHON) to investigate the mtDNA haplotypes associated with the primary mutation(s). Eleven patients carried the mitochondrial DNA (mtDNA) G11778A mutation, while one had the T14484C mutation; one patient had the G3460A mutation and one the G14459A mutation. The Iranian G11778A LHON mutation was not associated with two mtDNA haplogroups-M (0.0% compared with 3.2% in healthy controls) and J (7.7% compared with 10% in healthy controls). Our results showed a similarity in the pattern of LHON primary point mutations between Iranian families with LHON and those of Russian, European, and North American origin. Our results also do not support an association between mtDNA haplogroups J and M with LHON primary point mutations.

Lack of association between Leber's hereditary optic neuropathy primary point mutations and multiple sclerosis in Iran.

The hypothesis that mitochondrial genes may implicate susceptibility to multiple sclerosis (MS) is supported by an increasing number of case reports on Leber's hereditary optic neuropathy (LHON)-associated mitochondrial DNA (mtDNA) point mutations in patients with MS. A number of mtDNA mutations with primary pathogenic significance for LHON, a maternally inherited disease causing severe bilateral visual loss predominantly in young men, have been detected in patients with an MS-like phenotype. To evaluate the link between MS and LHON primary point mutations, we investigated 31 non-related Iranian clinically definite MS patients (23 females and 8 males) with optic nerve involvement, as well as 25 patients (16 females and 9 males) without involvement of the optic nerve as controls. Three patients had severe bilateral visual loss without any recovery. We searched for the presence of LHON mitochondrial mutations at nucleotide positions (np) 11,778, 3,460, and 14,484 by mutation-specific polymerase chain reaction and restriction fragment length polymorphism. Our results suggest that there is no association between Iranian patients with MS and mtDNA point mutations at np 11,778, 3,460, and 14,484.