Lack of Association between Leber’s Hereditary Optic Neuropathy Primary Point Mutations and Multiple Sclerosis in Iran

Population screening for association of mitochondrial haplogroups BM, J, K and M with multiple sclerosis: interrelation between haplogroup J and MS in Persian patients

Background: Multiple sclerosis (MS) is an immunological inflammatory disease of the central nervous system (CNS) which is chronically observed in young adults. On the basis of earlier studies, potential relatedness between MS and mitochondrial DNA (mtDNA) mutations was postulated. Materials and methods: 246 individuals were screened using the PCR-RFLP method, including 70 MS patients examined for mitochondrial haplogroups BM, J, K and M and 176, 149 and 70 normal controls examined for haplogroups BM and M, J and K, respectively. Results and discussion: Our analysis revealed a relatively high proportion of haplogroup BM in MS patients (∼26%) compared to normal controls (∼13%). In addition, a slightly significant increase of MS patients of haplogroup J (20% in MS patients versus 9.39% in normal controls at P-0.049), while haplogroups M and K did not show contribution to MS contingency (2.85 and 2.27%, respectively at P-1.000 in haplogroup M and 12.85 and 7.14% respectively at P-0.399 in haplogroup K).

Multiple sclerosis and mitochondrial gene variations: a review

Multiple sclerosis (MS) is a debilitating disease of the central nervous system. Its etiology is still an unanswered enigma; its symptoms are varied and unpredictable; and there is no cure for it. Genetics has been introduced as a contributing factor to MS. Not only may MS stem from nuclear gene variations/mutations, but also it may arise from mitochondrial gene variations/mutations. The association of mitochondrial DNA variations/mutations with the pathogenesis of MS has, so far, been analyzed by several studies. This paper reviews the literature with regard to MS and corresponding mitochondrial DNA variations.

Complex I deficiency in Persian multiple sclerosis patients

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system characterized by the morphological hallmarks of inflammation, demyelination and axonal loss. Until now, little attention has been paid to the contribution of mitochondrial respiratory chain enzyme activities to MS. In this study, kinetic analysis of mitochondrial respiratory chain complex I enzyme (measured as NADH-ferricyanide reductase) was performed on intact mitochondria isolated from fresh skeletal muscle in MS patients (n = 10) and control subjects (n = 11). Mitochondrial DNA common deletion and deletions were also tested in MS patients. Our findings showed that complex I activities were significantly reduced (P = 0.007) in patients compared with control. However, we could not find deletion in mtDNA of patients with MS. The presupposition of relationship between MS and mitochondrial disorders is due to predominant maternal transmission of MS in affected parent-child pairs, pathoaetiological role of respiratory chain dysfunction in multisystem disorders and important role of it in neurodegenerative disorders, a number of patients such as LHON or other mtDNA abnormality with developed neurological symptoms indistinguishable from MS and similarity of clinical symptoms in mitochondrial disorders to those of MS. This study suggested that a biochemical defect in complex I activity may be involved in pathogenesis of MS.