With the exception of seven genes, TPBG, TCIRG1, MDGA2, ATF7IP2, NTN1, MC5R, and NMB, associations with genes involved in eye morphogenesis (formation of the eye, morphology of the eye and retina, morphology of eye cells), physiology (preservation of cone cells, electrophysiology of the eye) and degeneration (retinal dystrophy, retina degeneration, degeneration of the eye) have been found. The gene discussed is MDGA2; the disease is inherited retinal dystrophy.