Objective: The contribution of the A3243G mutation in mitochondria DNA (mtDNA) to diabetes mellitus (DM) in Werner's syndrome (WS) was studied.
Patients and method: DNA samples from peripheral white blood cells (WBCs) originating from 24 Japanese WS patients aged 30-56 were used. For control, 239 subjects aged 15-95 were also used. The mtDNA was amplified using specific primers. After HaeIII digestion, the ratio of the A3243G mutation was compared.
Results: The ratio of the A3243G mutation is 0.45+/-0.13% in WS, which is statistically insignificant from those in the control groups at various age. The mutation types of WRN in genomic DNA did not affect the ratio of the A3243G mtDNA mutation. No significant difference was observed concerning to the ratios among the WS patients with and without DM, and also controls. Furthermore, no significant difference was observed in the ratios of A3243G mutation among controls from various age groups.
Conclusion: The A3243G mutation in mtDNA does not accumulated in WBCs from WS. Mitochondria A3243G mutation may not contribute to the pathogenesis of DM observed in WS.