Mckay et al. identified heterozygosity for a val162-to-met (V162M; 604,210.0010) mutation within the fourth EGF-like domain of the CRB1 gene in PPRCA patients that was very close to the mutated CRB1 gene locus in RP patients [2]. The gene discussed is EGF; the disease is retinitis pigmentosa 1.