Title:
Mitochondrial DNA Variation at Position 16189 and Diabetes

Description:
Mitochondrial DNA Variation at Position 16189 and Diabetes: Frequency Amongst South Eastern Kenyan Populations Mitochondrial dysfunction plays a critical role in the pathogenesis of insulin resistance and Diabetes Mellitus, and mitochondrial mutations have been reported to be a cause of maternally inherited diabetes and some features of metabolic syndrome. A substitution of thymidine for cytosine (T→C) at nucleotide position 16189C of the mitochondrial genome (mtDNA) may be associated with insulin resistance and type 2 Diabetes Mellitus. An analysis of subjects from five Asian countries confirmed an association between the 16189C variant and type 2 Diabetes Mellitus. However, a meta-analysis of previous research on European subjects did not show an association between the 16189C variant and disease expression. Due to the inconsistency of the results between the studies in Asians and Europeans; we decided to investigate other ethnic populations. DNA was extracted from cheek swab samples collected from the Mijikenda and Taita groups of southeast Kenya. The Hypervariable Region I of the mtDNA, where the mutation is found, was sequenced. The mutation is found at low frequencies in these Kenyan populations, 8.61% in the Taita sample and 9.62% in the Mijikenda sample. In contrast, previous studies indicated frequencies of 31.0% in Asian and 9.2% in European samples. Ethnic differences among populations may underlie risk association in a complex disease such as diabetes because the interaction between genes and environment, influences many aspects of the phenotype. It is not yet clear whether the 16189C variant is associated with diabetes risk, and specifically in Asian populations. It may be a risk factor for diabetes among Asian populations, and perhaps in other populations, but the specific metabolic effects of this mutation must be identified before definitive conclusions can be reached. It appears that mtDNA mutation at position 16189C is not a risk factor for the development diabetes, at least in south eastern Kenyans. Urban lifestyle patterns seem to be more influential in the development of diabetes in Kenyan populations. Association studies between diabetes and the 16189C mutation in other ethnic groups are needed as well.

Author:
oldebullhamster

Tags:
anthropology, diabetes, DNA, epidemiology, juan, kenya, mitochondrial, pablo, Physical,