MERTK and Leber congenital amaurosis: Mutations in several RPE-specific genes, including RPE65, LRAT (lecithin retinol acyltransferase) and MERTK (tyrosine-protein kinase Mer), have been identified in patients with early-onset retinal degeneration and LCA (Gal et al., 2000; Gu et al., 1997; Thompson et al., 2001).