Total color blindness, or achromatopsia, is generally an inherited disease caused by mutations in one of six different genes, with the majority of cases involving variants in either the CNGA3 or CNGB3 genes. The new gene therapy being trialed focuses on correcting a defect in the CNGA3 gene.
The treatment is somewhat similar to one of the first FDA-approved gene therapies, for vision loss, called Luxturna. These treatments attach a healthy functioning gene to a genetically modified harmless virus. The treatment is injected into a patient's eye and hopefully the correctly functioning gene begins producing whatever protein was previously missing, helping cure the condition caused by the defective gene.