Figure 3.

(A) Arrays with an OPN1LW gene followed by an OPN1MW gene, each with haplotypes that splice normally, give rise to L and M cones that have a normal amount of photopigment, which in turn confers normal, trichromatic red-green color vision. Exons are represented by the numbered rectangles, and the color-coding is the same as that described in Figure 2. (B) An array with a single OPN1LW_LIAVA gene does not produce any functional photopigment, so all cones except-S cones are devoid of pigment, and a male with this array is an obligate Blue Cone Monochromacy (BCM). (C) An array in which the first two genes have the LIAVA haplotype will cause BCM regardless of whether the second gene encodes an OPN1LW or OPN1MW gene (indicated by a yellow rectangle for exon 5) because all cones except S cones will be devoid of photopigment. (D) An array in which the first gene is OPN1LW_LIAVA and the second gene is either OPN1MW_MVVVA or OPN1MW_MIAVA will cause protanopia in males because the L cones will be devoid of photopigment, and the M cones will have photopigment. Thus, color vision will be mediated by M and S cones. (E) An array in which the OPN1LW gene has a normal (non-exon 3-skipping) haplotype and the second gene is an OPN1MW_LIAVA will cause deuteranopia in males because only L cones and S cones will contain functional photopigment. Arrays in this figure correspond to those found in patients described in Tables S1–S3 [22,27,31,33,39].