ENU-induced T to A transversion at base pair 5,909,150 (v38) on chromosome 11, or base pair 40,932 in the GenBank genomic region NC_000077 encoding Gck. The mutation corresponds to residue 898 in the mRNA sequence NM_010292.5 (c.898T>A) within exon 4 of 10 total exons. The mutation results in a methionine to lysine substitution at amino acid 139 (p.M139K) in the GCK protein.