ENU-induced A to T transversion at base pair 66,859,856 (v38) on chromosome 18, or base pair 632 in the GenBank genomic region NC_000084 for the Mc4r gene. The mutation corresponds to residue 632 in the mRNA sequence NM_016977 within exon 1 of 1 total exons. The mutation results in an asparagine to isoleucine substitution at position 62 (N62I) in the MC4R protein.