CNG channel deficiency is characterized by elevated cellular cGMP levels and increased activity of cGMP-dependent protein kinase G, which leads to Ca2+ turbulence, cone degeneration, and impaired cone function, including CNG channel beta 3/ACHM3 and CNG channel alpha 3.343,344 Other gene mutations include PDE6H and PDE6C, which have been discovered in RP sections. This evidence concerns the gene CNGB3 and hyperinsulinemic hypoglycemia, familial, 4.