Maternally inherited type 2 diabetes mellitus may be associated with mitochondrial tRNAThr mutations

Figure 1 Pedigrees of two Han Chinese families with maternally inherited type 2 diabetes mellitus. Squares indicate males, circles indicate females, filled symbols indicate affected individuals, and open symbols indicate unaffected individuals. Arrows denote the probands. DM: Diabetes mellitus.

Figure 2  Identification of the mitochondrial tRNA^Thr G15927A, G15930A, and A15951G mutations by direct Sanger sequencing.

Figure 3  Predicted cloverleaf structures of wild-type and mutant tRNA^Thr. The G15927A, G15930A, and A15951G mutations are indicated by arrows.

Figure 4 Assessment of mitochondrial functions in mutant and control cybrid cell lines. A: Adenosine triphosphate production; B: Mitochondrial membrane potential; C: Reactive oxygen species levels; D: NAD⁺/NADH ratio. ATP: Adenosine triphosphate; DM: Diabetes mellitus; MMP: Mitochondrial membrane potential; ROS: Reactive oxygen species.