In this study, we performed association analyses of the 13 newly identified mutations associated with the litter size of MG, and 7 known mutations in the BMPRIB, GDF9, BMP15, LEPR, and B4GALNT2 genes with litter size in UM, DPU, and SFKU sheep breeds/populations. The gene discussed is LEPR; the disease is myasthenia gravis.