PRPH2
Function
Essential for retina photoreceptor outer segment disk morphogenesis, may also play a role with ROM1 in the maintenance of outer segment disk structure (By similarity). Required for the maintenance of retinal outer nuclear layer thickness (By similarity). Required for the correct development and organization of the photoreceptor inner segment (By similarity).
Involvement in disease
Retinitis pigmentosa 7
RP7
A retinal dystrophy belonging to the group of pigmentary retinopathies. Retinitis pigmentosa is characterized by retinal pigment deposits visible on fundus examination and primary loss of rod photoreceptor cells followed by secondary loss of cone photoreceptors. Patients typically have night vision blindness and loss of midperipheral visual field. As their condition progresses, they lose their far peripheral visual field and eventually central vision as well.
None
The disease is caused by variants affecting the gene represented in this entry.
Retinitis punctata albescens
RPA
A form of fleck retina disease characterized by aggregation of white flecks posteriorly in the retina, causing night blindness and delayed dark adaptation. It differs from fundus albipunctatus in being progressive and evolving to generalized atrophy of the retina.
None
The disease is caused by variants affecting the gene represented in this entry.
Macular dystrophy, vitelliform, 3
VMD3
A form of vitelliform macular dystrophy, a retinal disease characterized by yellow, lipofuscin-containing deposits, usually localized at the center of the macula. Patients usually become symptomatic in the fourth or fifth decade of life with a protracted disease of decreased visual acuity.
None
The disease is caused by variants affecting the gene represented in this entry.
Macular dystrophy, patterned, 1
MDPT1
A form of retinal patterned dystrophy, a heterogeneous group of macular disorders that includes reticular (fishnet-like) dystrophy, macroreticular (spider-shaped) dystrophy and butterfly-shaped pigment dystrophy.
None
The disease is caused by variants affecting the gene represented in this entry.
Choroidal dystrophy, central areolar 2
CACD2
A form of central areolar choroidal dystrophy, a retinal disease that affects the macula and results in a well-demarcated circumscribed area of atrophy of the pigment epithelium and choriocapillaris.
None
The disease is caused by variants affecting the gene represented in this entry.
Defects in PRPH2 are found in different retinal diseases including cone-rod dystrophy, retinitis pigmentosa, macular degeneration. The mutations underlying autosomal dominant retinitis pigmentosa and severe macular degeneration are largely missense or small in-frame deletions in a large intradiscal loop between the third and fourth transmembrane domains. In contrast, those associated with the milder pattern phenotypes or with digenic RP are scattered more evenly through the gene and are often nonsense mutations. This observation correlates with the hypothesis that the large loop is an important site of interaction between PRPH2 molecules and other protein components in the disk.
Sequence Similarities
Belongs to the PRPH2/ROM1 family.
Tissue Specificity
Retina (photoreceptor). In rim region of ROS (rod outer segment) disks.
Cellular localization
- Membrane
- Multi-pass membrane protein
- Cell projection
- Cilium
- Photoreceptor outer segment
- Photoreceptor inner segment
Alternative names
PRPH, RDS, TSPAN22, PRPH2, Peripherin-2, Retinal degeneration slow protein, Tetraspanin-22, Tspan-22