This allele encodes a proline at position 5, an aspartic acid at position 20, a methionine at position 26, and an alanine at position 38. This allele is found on C57BL/6J, C57BL/10, AKR/N, AKR/J, DBA/2, SAMP3, SAMP8, SAMR2 backgrounds, also found in BTBR, BUB, C57BLKS, C57BR, C57L, C58, CASA, CAST, CE, CZECHII, DBA/1, JF1, MOLF, MA, MSM, NOD, PL, RIII, SEA, SWR.