ENU-induced T to A transversion at base pair 101,701,732 (v38) on chromosome 13, or base pair 66,486 in the GenBank genomic region NC_000079 encoding Pik3r1. The mutation corresponds to residue 1,436 in the mRNA sequence NM_001077495 within exon 6 of 16 total exons. The mutation results in a leucine to histidine substitution at residue 272 (L272H) in the p85 protein.