FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Human Disease Model Report: retinitis pigmentosa 12
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General Information
Name
retinitis pigmentosa 12
FlyBase ID
FBhh0000201
Disease Ontology Term
Parent Disease
Overview

This report describes retinitis pigmentosa 12 (RP12), which is a subtype of retinitis pigmentosa; RP12 exhibits autosomal recessive inheritance. The human gene implicated in this disease is CRB1, which plays a role in the morphogenesis of photoreceptor cells. CRB1 is also implicated in other diseases associated with retinal degeneration (MIM:604210). There is a single fly gene, crb, that is orthologous to both CRB1 and CRB2, and for which classical amorphic and hypomorphic alleles, RNAi-targeting constructs, and alleles caused by insertional mutagenesis have been generated. See also the report for 'retinal disease, CRB1-related' (FBhh0000572) for additional information on experimental results using Drosophila models of this and related diseases.

Experiments characterizing mutations in the fly gene analogous to variants implicated in human retinal disease include several implicated in retinitis pigmentosa 12. Variant(s) implicated in human disease tested (as analogous mutation in fly gene): C749W in the fly crb gene (corresponds to C250W in the human CRB1 gene, implicated in RP12); T1283M in the fly crb gene (corresponds to T745M in the human CRB1 gene, implicated in RP12); N1486S in the fly crb gene (corresponds to N894S in the human CRB1 gene, implicated in RP12); C1540Y in the fly crb gene (corresponds to C948Y in the human CRB1 gene, implicated in RP12 and Leber congenital amaurosis 8).

[updated Apr. 2018 by FlyBase; FBrf0222196]

Disease Summary Information
Parent Disease Summary: retinitis pigmentosa
Symptoms and phenotype

Retinitis pigmentosa (RP) refers to a heterogeneous group of inherited ocular diseases that result in a progressive retinal degeneration affecting 1 in 3,000 to 5,000 people (Veltel et al., 2008; pubmed:18376416). Symptoms include night blindness, the development of tunnel vision, and slowly progressive decreased central vision starting at approximately 20 years of age. [from MIM:268000; 2016.03.07]

The rate and extent of disease progression vary markedly among RP patients, in some cases, even within the same family. [from MIM:600059; 2020.08.04]

Specific Disease Summary: retinitis pigmentosa 12
OMIM report

[RETINITIS PIGMENTOSA 12; RP12](https://omim.org/entry/600105)

Human gene(s) implicated

[CRUMBS CELL POLARITY COMPLEX COMPONENT 1; CRB1](https://omim.org/entry/604210)

Symptoms and phenotype

See general description above.

Genetics

Retinitis pigmentosa 12 is caused by homozygous or compound heterozygous mutations in the crumbs 1, cell polarity complex component (CRB1) gene. [from MIM:600105; 2016.03.09]

Cellular phenotype and pathology
Molecular information

The ortholgous crb gene in Drosophila plays a role in establishing apical-basal polarity in epithelial cells, including in differentiating photoreceptors.

The CRB1 protein localizes to the inner segment of mammalian photoreceptors in the retina and appears to play a role in photoreceptor morphogenesis. [from MIM:604210; 2016.03.15]

External links
Disease synonyms
retinitis pigmentosa
retinitis pigmentosa 12, autosomal recessive
RP12
Ortholog Information
Human gene(s) in FlyBase
    Human gene (HGNC)
    D. melanogaster ortholog (based on DIOPT)
    Comments on ortholog(s)

    Many to one: 2 human to 1 Drosophila; the second orthologous human gene is CRB2.

    Other mammalian ortholog(s) used
      D. melanogaster Gene Information (1)
      Gene Snapshot
      crumbs (crb) encodes a transmembrane protein that binds to multiple proteins such as those encoded by sdt, par-6, AP-2α, yrt, ex and Moe. It contributes to organization of zonula adherens, epithelial morphogenesis, apico-basal cell polarity, and is a negative regulator of Notch activity and growth control via the Hippo pathway. In photoreceptor cells it is involved in morphogenesis, the trafficking of the product of ninaE and prevention of light-dependent photoreceptor degeneration. [Date last reviewed: 2019-03-07]
      Gene Groups / Pathways
      Comments on ortholog(s)

      Moderate-scoring ortholog of human CRB1 (reciprocal best hit) and CRB2 (1 Drosophila to 2 human). Dmel\crb shares 28-30% identity and 40-43% similarity with the human genes. In invertebrates, the orthologous genes are longer than in vertebrates, with additional laminin and EGF-like domains.

      Orthologs and Alignments from DRSC
      DIOPT - DRSC Integrative Ortholog Prediction Tool - Click the link below to search for orthologs in Humans
      Other Genes Used: Viral, Bacterial, Synthetic (0)
        Summary of Physical Interactions (24 groups)
        protein-protein
        Interacting group
        Assay
        References
        phenotype-based detection assay, fluorescence microscopy, inferred by author, pull down, western blot, anti tag western blot
        proximity ligation assay, fluorescence microscopy, anti bait coimmunoprecipitation, western blot, ubiquitin reconstruction
        pull down, autoradiography
        pull down, western blot, anti tag coimmunoprecipitation, anti tag western blot
        anti tag coimmunoprecipitation, western blot
        anti tag coimmunoprecipitation, peptide massfingerprinting
        pull down, autoradiography, two hybrid, anti tag coimmunoprecipitation, anti tag western blot
        pull down, anti tag western blot, anti tag coimmunoprecipitation
        anti tag coimmunoprecipitation, western blot, pull down, anti tag western blot
        anti tag coimmunoprecipitation, western blot, pull down, anti tag western blot
        pull down, anti tag western blot, anti tag coimmunoprecipitation
        anti bait coimmunoprecipitation, western blot
        anti tag coimmunoprecipitation, western blot
        anti bait coimmunoprecipitation, western blot
        proximity ligation assay, fluorescence microscopy
        nuclear magnetic resonance, pull down, western blot, anti tag coimmunoprecipitation, two hybrid, x-ray crystallography, phenotype-based detection assay, fluorescence microscopy, inferred by author
        anti tag coimmunoprecipitation, western blot, anti bait coimmunoprecipitation, peptide massfingerprinting, proximity ligation assay, fluorescence microscopy, pull down, autoradiography
        pull down, anti tag western blot
        two hybrid, anti bait coimmunoprecipitation, western blot, peptide massfingerprinting, anti tag coimmunoprecipitation, pull down, autoradiography, coimmunoprecipitation
        anti tag coimmunoprecipitation, anti tag western blot
        anti tag coimmunoprecipitation, anti tag western blot
        anti tag coimmunoprecipitation, anti tag western blot
        anti tag coimmunoprecipitation, anti tag western blot
        far western blotting, autoradiography, anti bait coimmunoprecipitation, western blot, anti tag coimmunoprecipitation, anti tag western blot, pull down
        Alleles Reported to Model Human Disease (Disease Ontology) (12 alleles)
        Models Based on Experimental Evidence ( 7 )
        Allele
        Disease
        Evidence
        References
        Modifiers Based on Experimental Evidence ( 6 )
        Alleles Representing Disease-Implicated Variants
        Genetic Tools, Stocks and Reagents
        Sources of Stocks
        Contact lab of origin for a reagent not available from a public stock center.
        Bloomington Stock Center Disease Page
        Related mammalian, viral, bacterial, or synthetic transgenes
        Allele
        Transgene
        Publicly Available Stocks
        Selected Drosophila transgenes
        Allele
        Transgene
        Publicly Available Stocks
        RNAi constructs available
        Allele
        Transgene
        Publicly Available Stocks
        Selected Drosophila classical alleles
        Allele
        Allele class
        Mutagen
        Publicly Available Stocks
        ethyl methanesulfonate
        loss of function allele
        CRISPR/Cas9
        loss of function allele
        CRISPR/Cas9
        amorphic allele - genetic evidence
        ethyl methanesulfonate
        amorphic allele - genetic evidence
        X ray
        amorphic allele - genetic evidence
        X ray
        amorphic allele - genetic evidence
        X ray
        amorphic allele - genetic evidence
        X ray
        amorphic allele - genetic evidence
        ethyl methanesulfonate
        amorphic allele - genetic evidence
        X ray
        amorphic allele - genetic evidence
        X ray
        amorphic allele - genetic evidence
        X ray
        loss of function allele
        References (9)