This spontaneously arising frameshift deletion is located in exon 2 at position 103308576 bp (NCBI Build 37) and results in a premature stop codon. The mutation is predicted to result in a truncated protein lacking the transmembrane domains 4-7. The inbred strains BDP/J, DBA/1J, DBA/2J, I/LnJ, FVB/NJ, LG/J, MRL/MpJ, NODShi/LtJ, NOR/LtJ, P/J, PL/J, SKHIN/Sprd, SJL/J, SM/J are homozygous for the deletion. The allele is segregating in the outbred stocks ICR and CD-1.