PDE6C and retinitis pigmentosa: Additionally, polymorphisms in several genes that could potentially influence retinitis pigmentosa development, including Rpgrip1, Rpgr, Gngt1, Agtpbp1, Grin2a, Syngap1, Slc24a2, Slc24a4, Cacnb4, Cacna1e, Cacna1c, Cacna2d4, Cacnb2, Cib2, Pde6c, Pde6g, and Ppef2, were further analyzed to predict their functional relevance.