Leber Congenital Amaurosis 8 / Retinitis Pigmentosa 12 / Pigmented Paravenous Chorioretinal Atrophy (CRB1)
CRB1-associated retinal dystrophies comprise three different eye disorders, called retinitis pigmentosa, Leber congenital amaurosis and pigmented paravenous chorioretinal atrophy. These diseases are inherited in an autosomal recessive manner and are caused by pathogenic variants in the gene CRB1. Pathogenic CRB1 variants do not appear to be prevalent in specific populations. Retinitis pigmentosa presents with night blindness, which usually begins in early childhood, and progresses to tunnel vision and blindness later in adulthood. Leber congenital amaurosis is more severe than retinitis pigmentosa and manifests in infancy. Patients have profound loss of vision at an early age. Pigmented paravenous chorioretinal atrophy can lead to a progressive loss of eyesight in some patients, but most will not develop any symptoms. Males are often affected more severely than females. Life expectancy is not reduced. Some pathogenic variants have been associated with the development of a specific retinal dystrophy, and therefore the phenotype may be able to be predicted in some patients based on the genotype.
For information about carrier frequency and residual risk, please see the residual risk table.