Frameshift deletion (20bp) of 4:1029027..1029046 resulting in the addition of AAGRYQNAGRPDPFCATLYHGHVFFGATLQRRAHRPNPAAHS after valine 68 of the only Mpv17 isoform and premature truncation following these novel amino acids. This deletion also affects asRNA:CR44031 on the opposite strand: the deletion is within the second exon of asRNA:CR44031 resulting in the loss of bases 338 through 357 of the asRNA:CR44031 RA transcript and bases 366 through 385 of the RB transcript.