Abstract
Recently it has been reported that Mt5178A (a C-to-A transversion at nucleotide position 5178 within the NADH dehydrogenase subunit 2 gene) is related to longevity, and the individuals with Mt5178C are more susceptible to adult-onset diseases than those with Mt5178A. Oxidative stress plays an essential role in the destruction of pancreatic islet cells in type 1 diabetes mellitus. To evaluate the effect of mitochondrial DNA variations on the occurrence of type 1 and type 2 diabetes, we analyzed the incidence of Mt5178A/Mt5178C by PCR-RFLP with Alu I in 385 type 1 diabetic patients, 687 type 2 diabetic patients, and 469 healthy controls. The frequency of Mt5178A was significantly lower in type 1 diabetic patients (121/385, 31.4%) than in healthy controls (184/469, 39.2%) (p=0.018). There were no associations of the Mt5178A/Mt5178C ratio with HLA-DR4, DR9, DQ3 and DQ4 as representative HLA class II in type 1 diabetic patients. On the other hand, the frequency of Mt5178A in type 2 diabetic patients (281/689, 40.9%) was similar to that in healthy controls. These findings suggest that the individual with Mt5178C is susceptible to type 1 diabetes.
