MedGen

Cone-rod dystrophy (CORD) and retinitis pigmentosa (RP) are clinically and genetically overlapping heterogeneous retinal dystrophies. RP is characterized initially by rod photoreceptor dysfunction, giving rise to night blindness, which is followed by progressive rod and cone photoreceptor dystrophy, resulting in midperipheral vision loss, tunnel vision, and sometimes blindness. In contrast to RP, CORD is characterized by a primary loss of cone photoreceptors and subsequent or simultaneous loss of rod photoreceptors. The disease in most cases becomes apparent during primary-school years, and symptoms include photoaversion, decrease in visual acuity with or without nystagmus, color vision defects, and decreased sensitivity of the central visual field. Because rods are also involved, night blindness and peripheral vision loss can occur. The diagnosis of CORD is mainly based on electroretinogram (ERG) recordings, in which cone responses are more severely reduced than, or equally as reduced as rod responses (summary by Estrada-Cuzcano et al., 2012). [from OMIM]

Any retinitis pigmentosa in which the cause of the disease is a mutation in the MAK gene. [from MONDO]

Any retinitis pigmentosa in which the cause of the disease is a mutation in the PRPF6 gene. [from MONDO]

Retinitis pigmentosa (RP) describes a group of disorders with progressive degeneration of rod and cone photoreceptors in a rod-cone pattern of dysfunction. RP has a prevalence of 1 in 3,500, and is genetically and phenotypically heterogeneous (summary by Mackay et al., 2010). For a general phenotypic description and a discussion of genetic heterogeneity of retinitis pigmentosa, see 268000. [from OMIM]

Any retinitis pigmentosa in which the cause of the disease is a mutation in the DHDDS gene. [from MONDO]

Any retinitis pigmentosa in which the cause of the disease is a mutation in the GUCA1B gene. [from MONDO]

Retinitis pigmentosa-43 (RP43) is characterized by night blindness in the first decade of life, with progressive loss of peripheral visual fields and reduction in visual acuity. Examination reveals typical features of RP, including waxy pallor of optic disc, attenuated retinal vessels, and bone-spicule pigment in midperipheral retina. Macular edema and/or atrophy has been observed in some patients. Electroretinographic responses are markedly reduced or absent (summary by Huang et al., 1995 and Corton et al., 2010). [from OMIM]

Retinitis pigmentosa-39 (RP39) is characterized by the typical features of RP, including constriction of visual fields and reduced vision, with the fundus showing bone-spicule pigment deposition and attenuation of retinal vessels (Kaiserman et al., 2007; Jung et al., 2023). For a general phenotypic description and a discussion of genetic heterogeneity of retinitis pigmentosa (RP), see 268000. [from OMIM]

Any retinitis pigmentosa in which the cause of the disease is a mutation in the PDE6B gene. [from MONDO]

Any retinitis pigmentosa in which the cause of the disease is a mutation in the RPE65 gene. [from MONDO]

Any retinitis pigmentosa in which the cause of the disease is a mutation in the RGR gene. [from MONDO]

Any retinitis pigmentosa in which the cause of the disease is a mutation in the CNGB1 gene. [from MONDO]

Retinitis pigmentosa-47 (RP47) is characterized by relatively late-onset visual decline, although most patients experience night blindness in childhood. A characteristic golden sheen, considered to be pathognomonic for Oguchi disease (258100), may be observed in the periphery on ultra-widefield fundus images (Nishiguchi et al., 2019). For a phenotypic description and a discussion of genetic heterogeneity of retinitis pigmentosa, see 268000. [from OMIM]

Any retinitis pigmentosa in which the cause of the disease is a mutation in the RHO gene. [from MONDO]

Any retinitis pigmentosa in which the cause of the disease is a mutation in the ZNF513 gene. [from MONDO]

Retinitis pigmentosa-56 (RP56) is an early-onset form of RP with progressive visual-field loss and deterioration of visual acuity (Bandah-Rozenfeld et al., 2010). For a general phenotypic description and a discussion of genetic heterogeneity of retinitis pigmentosa, see 268000. [from OMIM]

Any retinitis pigmentosa in which the cause of the disease is a mutation in the ARL6 gene. [from MONDO]

Any retinitis pigmentosa in which the cause of the disease is a mutation in the TTC8 gene. [from MONDO]

Retinitis pigmentosa-54 (RP54) is characterized by typical signs of RP, including poor night vision and peripheral field loss, retinal bone spicule-type pigment deposits, pale optic discs, and markedly reduced or extinguished responses on electroretinography. Atypical features that have been observed include early degeneration of the cone photoreceptor system with macular abnormalities, and ring scotoma on the visual field (Collin et al., 2010). Patients may exhibit an early-onset form of cone-rod dystrophy (CORD23), with central vision loss and ring scotoma around the fovea that progresses to marked chorioretinal atrophy in the macular area (Serra et al., 2019). For a general phenotypic description and a discussion of genetic heterogeneity of retinitis pigmentosa, see 268000. For a general phenotypic description and discussion of genetic heterogeneity of cone-rod dystrophy, see CORD2 (120970). [from OMIM]

Any retinitis pigmentosa in which the cause of the disease is a mutation in the KLHL7 gene. [from MONDO]