The genes bone morphogenetic protein receptor, type IB (BMPR1B) at 17,819,265–17,978,113 bp on CFA32 and paired related homeobox 2 (PRRX2) at 54,091,700–54,224,620 bp on CFA9 in two regions containing long-range homozygous haplotypes were previously reported as candidate genes for polydactyly in mice. The gene discussed is BMPR1B; the disease is polydactyly.