CACNA1F

Variants (also called mutations) in the CACNA1F gene have been identified in people with X-linked congenital stationary night blindness. CACNA1F gene variants are responsible for the incomplete form of the disorder. People with this form of the disorder have vision problems such as increased sensitivity to light (photophobia), a loss of sharpness (reduced acuity), involuntary movements of the eyes (nystagmus). Many affected individuals also have difficulty seeing in low light (night blindness).

Variants in the CACNA1F gene change the structure of the alpha-1 subunit. These changes make it difficult for CaV1.4 channels to transport calcium ions across the cell membrane of photoreceptor cells. A loss of calcium ion transport disrupts the ability of both rods and cones to transmit visual signals, which impairs vision in people with X-linked congenital stationary night blindness.

MedlinePlus Genetics provides information about Cone-rod dystrophy

Variants in the CACNA1F gene can cause another rare disorder that impairs vision known as Åland Islands eye disease. This condition causes vision problems similar to those seen in people with X-linked congenital stationary night blindness.

Researchers have identified at least one CACNA1F gene variant that can cause Åland Islands eye disease (also known as Forsius-Eriksson syndrome). This condition was first described in a family from the Åland Islands, which are in the Baltic Sea off the coast of Sweden. Åland Islands eye disease is characterized by reduced visual acuity, nystagmus, an irregular curvature of the front part of the eye (astigmatism), nearsightedness (myopia), abnormal color vision, and night blindness. The variant associated with this disorder deletes a segment of genetic material from the CACNA1F gene. This deletion significantly alters the structure of the alpha-1 subunit of CaV1.4 channels and makes it difficult for calcium ions to move across the cell membrane of photoreceptor cells. A loss of calcium ion transport disrupts the ability of both rods and cones to transmit visual signals, leading to the vision problems seen in people with Åland Islands eye disease.