PRCD and retinitis pigmentosa 1: To date, only two RP-causing mutations of the PRCD gene have been reported in humans: a homozygous missense mutation (c.5G>A p.C2Y) in a single patient from Bangladesh and a homozygous nonsense mutation (c.64C>T p.R22X) in patients with RP in a small Arab village [3,5].