This naturally occurring strain-specific allele is the major allele and represents the G variant of coding SNP rs30712233 and the T variant of splice region SNP rs49812611 and is found in the reference C57BL/6J strain and in AKR/J and 129S1/SvImJ and others. These variants are A and C, respectively, in DBA/2J, C3H/HeJ and BALB/cByJ and others. The rs30712233-G variant (c.1976C) codes for a threonine codon at 659 (ACT) (p.T659) and the rs49812611-T splicing variant at the 9th nucleotide of intron 19 (c.1875+9A) enables normal splicing.