Disease name: ABCA4 Retinopathy
ICD-10 Disease Code: H35.53 - Other dystrophies primarily involving the sensory retina
ICD-10 Disease Group: H35 - Other retinal disorders
General description:ABCA4-related retinopathies are a group of inherited eye disorders caused by variants in the ABCA4 gene. ABCA4 encodes a protein found in the retina, specifically in the light-sensitive photoreceptor cells. This protein helps transport potentially harmful substances that form after phototransduction, the process where light is converted into electrical signals for the brain. Health conditions related to variants in ABCA4 include Stargardt disease, cone-rod dystrophy, juvenile age-related macular degeneration and retinitis pigmentosa.
Cone-rod dystrophy is a group of eye disorders that lead to progressive vision loss, affecting the retina's light-sensitive cells. There are over 30 types of cone-rod dystrophy, varying by genetic cause and inheritance pattern, and it can occur either alone or as part of a broader syndrome. Mutations in the ABCA4 gene are the leading cause of autosomal recessive cone-rod dystrophy. Additionally, at least 10 different genes have been linked to cone-rod dystrophy inherited through an autosomal dominant pattern.
Mutations:All ABCA4-related retinopathies are caused by different variants in the ABCA4 gene.
Disease frequency:Cone-rod dystrophy is estimated to affect approximately 1 in 30,000 to 40,000 individuals globally.
Symptoms:Symptoms of cone-rod dystrophy typically begin in childhood, with reduced visual sharpness and increased sensitivity to light. Over time, individuals experience impaired colour vision, central blind spots, and partial peripheral vision loss. As the disease progresses, night blindness and further peripheral vision decline can limit mobility, and most affected individuals become legally blind by mid-adulthood. Involuntary eye movements (nystagmus) may also develop.
Treatment:There is currently no cure for ABCA4-related retinopathies. Management focuses on slowing the degenerative process, addressing complications, and providing visual rehabilitation. Additionally, support is offered to help patients cope with the social and psychological challenges associated with vision loss. To slow disease progression, preventive measures include wearing sunglasses to reduce overexposure to visible light and avoiding vitamin A supplements. Regular eye exams are also recommended.
