Unilateral retinitis pigmentosa occurring in an individual with a germline mutation in the RP1 gene.

R etinitis pigmentosa (RP) is a heterogeneous group of monogenic retinal disorders characterized by progressive rod and then cone photoreceptor degeneration. Although female carriers of mutations in the X-linked genes RP2 and RP3 show asymmetry, cases due to mutations of autosomal genes show a high degree of symmetry between eyes. Patients with unilateral RP have been described, but none of these cases have been reported to be familial or associated with a gene mutation and the cause of these cases remains unclear. We describe the phenotype of a patient with entirely unilateral disease despite the inheritance of a germline mutation.