Multiple Sclerosis Disease and Mitochondria
Multiple Sclerosis (MS) is a multifocal demyelinating central nervous system disorder. To assess relationship between mtDNA haplogroups and MS, we have sequenced the mtDNA HVS-I in 54 MS patients and 100 control subjects. In this study, kinetic analysis of mitochondrial respiratory chain complex I enzyme was performed on intact mitochondria isolated from fresh skeletal muscle in MS patients (n =10) and control subjects (n =11). The frequencies of the Asian (M, BM) and European (N, J, K) mtDNA haplogroups in five major regions of Iran was investigated. Unexpectedly, the frequencies of the Asian haplogroups M and BM were low in Iran (2.34% for haplogroup M; 17.6% for haplogroup BM and 80.06% for haplogroup N).
We have found that haplogroups A and K are significantly more abundant in MS patients (P=0.042 for haplogroup A and P=0.0005 for haplogroup K). 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. Our results revealed that 15 (75%) out of 20 MS patients had point mutations. This study suggested that point mutation occurred in mtDNA might be involved in pathogenesis of MS. Our data suggest that Iranian tribes probably played a remarkable role in the formation of these ethnic groups. It gives the indication that the haplogroup J may be older than 6000-10000 years, and probably developed in Iran, and then expanded to different regions in Europe and Northwest Asia.
Of personal interest to me as an MS sufferer. Yet again, MtDNA shows itself to be non neutral.