cone-rod dystrophy 3

Cone-rod dystrophy 3 is an inherited retinal condition that primarily affects the light-sensing cells of the eye. It is caused by mutations in the ABCA4 gene, which disrupts the normal processing and clearance of visual cycle byproducts in photoreceptor cells. The disorder follows an autosomal recessive inheritance pattern, meaning that an affected individual must inherit changes in both copies of the gene. Precise prevalence estimates are not well established, and individuals may experience a range of visual difficulties over time.

Individuals with cone-rod dystrophy 3 typically experience a persistent color vision defect, a hallmark feature seen in all affected persons. Many also develop visual impairments such as bull's eye maculopathy, central scotomas, and peripheral visual field loss, with these features occurring in roughly 30 to 79 percent of cases. Visual symptoms may progress gradually, leading to challenges with tasks that depend on accurate color perception and a clear central vision. Not all individuals experience all features, and severity varies considerably.

Cone-rod dystrophy 3 is caused by mutations in the ABCA4 gene, which is essential for the normal functioning of the retina by helping to clear potentially toxic byproducts from the visual cycle. The disruption of this gene's function leads to the gradual deterioration of cone and rod photoreceptors, resulting in the visual deficits observed in affected individuals. This condition is inherited in an autosomal recessive manner, which means that a person must inherit a mutated copy of the gene from each parent to develop the disease. Families are encouraged to seek genetic counseling to understand the implications for family planning and to explore testing options. Associated genes include ABCA4.