Achromatopsia 4, also known as achm4, is related to cone dystrophy and achromatopsia. An important gene associated with Achromatopsia 4 is GNAT2 (G Protein Subunit Alpha Transducin 2), and among its related pathways/superpathways are Visual Cycle in Retinal Rods and Phosphodiesterases in neuronal function. Affiliated tissues include retina, and related phenotypes are nystagmus and visual impairment