Mutations associated with the CNGB3 subunit are most common in European subjects (ACHM3; OMIM# 262300) and account for 50% of all known cases worldwide, whereas the CNGA3-associated achromatopsia (ACHM2; OMIM# 216900) accounts for ~30% of all diagnosed cases thus far. This evidence concerns the gene CNGA3 and achromatopsia.