This phenotypic mutant was identified in an ENU mutagenesis screen and did not complement Myo7a. The mutation is a G to A transition at position 5472+5 (reference sequence NM_008663), the fifth position in intron 42. As a result, a cryptic splice site in intron 42 is used resulting in a 49bp insertion between exon 42 and exon 43 and a predicted premature truncation after the first 56 amino acids of the FERM2 domain. This mutation is uniquely present in all mice homozygous for this allele.