USH2A and Cone rod dystrophy: In two of the families (W09–0049 and W09–0050), genes residing in the largest homozygous regions (family with sequence similarity 161, member A [FAM161A], ABCA4, retinal pigment epithelium-specific protein 65 kDa [RPE65], Usher syndrome 2A (autosomal recessive, mild) [USH2A], and progressive rod-cone degeneration [PRCD]) were excluded.