The majority of genes (13/19) known to account for some form of LCA, including GUCY2D, encode photoreceptor specific proteins (den Hollander et al., 2008; Wang et al., 2009; Estrada-Cuzcano et al., 2011; Sergouniotis et al., 2011; Abu-Safieh et al., 2013). The gene discussed is GUCY2D; the disease is Leber congenital amaurosis.