(A) Muscle glycogen, (B) blood glucose, and (C) insulin levels in humans with the PPP1R3A FS mutation before and after two standardised meals (given at 60 and 240 min). Data from PPP1R3A FS carriers (n = 4; open circles) are compared with those from volunteers without diabetes (n = 9; solid squares) and from participants with type 2 diabetes (T2DM; n = 9; filled triangles). Mean data from two digenic participants (double heterozygotes for the PPP1R3A FS and PPARG FS) are included in graphs (A) and (B). Mean fasting insulin levels from the two digenic individuals were 199, 5,744, 9,534, 1,303, 13,689, and 10,291 pmol/l, too high to include in (C), at 0, 60, 120, 240, 360, and 480 minutes, respectively.