Genetic Association of Mitochondrial DNA Polymorphisms with Type 2 Diabetes Mellitus

Background: Although many single nucleotide polymorphisms (SNPs) of mtDNA h ave been found to be associated with type 2 diabetes mellitus, the results of studies using different population samples and different methods are mixed. Therefore, we conducted a genetic association study of mtDNA SNPs and type 2 diabetes mellitus in a Korean sample and compared our results with those of studies co nducted in other human populations. Methods: A total of 298 blood samples from 147 type 2 diabetic patients and 151 normal controls were surveyed for SNPs via PCR directed sequencing. Sequencing analy ses were performed using the SeqMan module of the DNASTAR program. The identified SNPs were compared to previously reported SNP lists on NCBI and V-mitoSNP. Results: A total of 24 SNPs were identified in the MT-RNR2, MR-TL1 and MT-ND1 mtDNA genes in Korean type 2 diabetes mellitus patients and normal controls. The SNPs identified in the Korean sample were not closely associated with the type 2 diabetes mellitus phenotype, a significantly different result from those previously observed in European, Chinese and Japanese samples. Additionally, a haplotype and prevalence analysis could not detect any differences between the type 2 diabetes mellitus patients and normal controls. Conclusion: The 24 mtDNA SNPs were not associ ated with type 2 diabetes mellitus risk in our Korean sample. The results of the present study support the possibilit y that mtDNA SNPs have a differential effect on the risk of type 2 diabetes mellitus according to geographical origin. (Korean Diabetes J 33:382-391, 2009)