Group differences. A, Warmth detection thresholds were significantly lower in the carriers than in the controls (p < 0.001); Ncarriers = 22 (11 females), Nwild types = 34 (17 females). B, Carriers displayed lower cool detection threshold than the wild types (p < 0.03); Ncarriers = 21 (10 female), Nwild types = 34 (16 females). C, Carriers tended to display lower cold detection thresholds than the wild types (p = 0.095); Ncarriers = 22 (11 females), Nwild types = 35 (17 females). Raw data are displayed for each group. Circles, Carriers (white: c.918–919insA; black: c.934C→T); diamonds, wild types. Bars represent mean ± SD.