Fig. 3.

PRPH contains nine exons. The wild-type (WT) protein consists of a head domain expressed by exon 1, a rod domain expressed by exons 2–7, and a tail domain expressed by exons 7–9. The PRPH splice donor variant rs73112142-A is in the first base site after the fifth exon. Defective splicing generates two truncated frameshift variant proteins. In both cases the truncated proteins retain the first 332 amino acids; then, either four extra base pairs are added at the end of exon 5 putting protein out of frame after exon 5 and creating a STOP after 93 amino acids (coded by exons 6 and 7), or read-through into intron 5 occurs, with STOP after 35 amino acids (encoded by intron 5)