In the specimens from individuals with idiopathic INS or INS associated with albinism, the mean areas of the NMJs found on fast MyHC–positive myofibers were 68.7% and 73.4% smaller, respectively, significantly different from the age-matched control values (Fig. 3A; both at P = 0.0001). The gene discussed is MYH6; the disease is albinism.