Incidental Mutation 'P0017:Crb1'
ID7823
Institutional Source Beutler Lab
Gene Symbol Crb1
Ensembl Gene ENSMUSG00000063681
Gene Namecrumbs family member 1, photoreceptor morphogenesis associated
Synonyms7530426H14Rik, A930008G09Rik
MMRRC Submission 038270-MU
Accession Numbers

Ncbi RefSeq: NM_133239.2; MGI: 2136343

Is this an essential gene? Probably non essential (E-score: 0.236) question?
Stock #P0017 (G1)
Quality Score
Status Validated
Chromosome1
Chromosomal Location139197056-139377100 bp(-) (GRCm38)
Type of Mutationmissense
DNA Base Change (assembly) T to C at 139248940 bp
ZygosityHeterozygous
Amino Acid Change Glutamic Acid to Glycine at position 435 (E435G)
Ref Sequence ENSEMBL: ENSMUSP00000142702 (fasta)
Gene Model predicted gene model for transcript(s): [ENSMUST00000059825] [ENSMUST00000196402] [ENSMUST00000198445] [ENSMUST00000200340]
Predicted Effect possibly damaging
Transcript: ENSMUST00000059825
AA Change: E435G

PolyPhen 2 Score 0.638 (Sensitivity: 0.87; Specificity: 0.91)
SMART Domains Protein: ENSMUSP00000060769
Gene: ENSMUSG00000063681
AA Change: E435G

DomainStartEndE-ValueType
low complexity region 8 19 N/A INTRINSIC
EGF 72 107 5.97e-4 SMART
EGF 112 145 9.19e-5 SMART
EGF_CA 147 183 2.89e-11 SMART
EGF_CA 185 221 1.14e-9 SMART
EGF_CA 223 259 2.26e-13 SMART
EGF_CA 261 298 5.15e-8 SMART
EGF 303 336 8.12e-6 SMART
EGF 341 394 2.6e-4 SMART
EGF_CA 396 438 2.54e-7 SMART
EGF 443 480 1.47e-3 SMART
LamG 505 650 1.75e-9 SMART
EGF 674 707 6.5e-5 SMART
LamG 734 859 1.05e-7 SMART
EGF 889 922 1.19e-3 SMART
LamG 971 1104 6.85e-12 SMART
EGF 1141 1174 7.07e-6 SMART
EGF_CA 1176 1211 3.01e-9 SMART
EGF 1216 1249 3.57e-2 SMART
EGF 1257 1294 6.92e0 SMART
EGF_CA 1296 1332 4.19e-8 SMART
transmembrane domain 1346 1368 N/A INTRINSIC
Predicted Effect possibly damaging
Transcript: ENSMUST00000196402
AA Change: E435G

PolyPhen 2 Score 0.638 (Sensitivity: 0.87; Specificity: 0.91)
SMART Domains Protein: ENSMUSP00000142702
Gene: ENSMUSG00000063681
AA Change: E435G

DomainStartEndE-ValueType
low complexity region 8 19 N/A INTRINSIC
EGF 72 107 5.97e-4 SMART
EGF 112 145 9.19e-5 SMART
EGF_CA 147 183 2.89e-11 SMART
EGF_CA 185 221 1.14e-9 SMART
EGF_CA 223 259 2.26e-13 SMART
EGF_CA 261 298 5.15e-8 SMART
EGF 303 336 8.12e-6 SMART
EGF 341 394 2.6e-4 SMART
EGF_CA 396 438 2.54e-7 SMART
EGF 443 480 1.47e-3 SMART
LamG 505 650 1.75e-9 SMART
EGF 674 707 6.5e-5 SMART
Predicted Effect probably benign
Transcript: ENSMUST00000197035
Predicted Effect probably benign
Transcript: ENSMUST00000198445
AA Change: E374G

PolyPhen 2 Score 0.421 (Sensitivity: 0.89; Specificity: 0.90)
SMART Domains Protein: ENSMUSP00000142552
Gene: ENSMUSG00000063681
AA Change: E374G

DomainStartEndE-ValueType
low complexity region 8 19 N/A INTRINSIC
EGF 72 107 5.97e-4 SMART
EGF 112 145 9.19e-5 SMART
EGF_CA 147 183 2.89e-11 SMART
EGF_CA 185 221 1.14e-9 SMART
EGF_CA 223 259 2.26e-13 SMART
EGF_CA 261 298 5.15e-8 SMART
EGF 303 333 1.63e1 SMART
EGF_CA 335 377 2.54e-7 SMART
EGF 382 419 1.47e-3 SMART
LamG 444 589 1.75e-9 SMART
EGF 613 646 6.5e-5 SMART
LamG 673 798 1.05e-7 SMART
EGF 828 861 1.19e-3 SMART
LamG 910 1043 6.85e-12 SMART
EGF 1080 1113 7.07e-6 SMART
EGF_CA 1115 1150 3.01e-9 SMART
EGF 1155 1188 3.57e-2 SMART
EGF 1196 1233 6.92e0 SMART
EGF_CA 1235 1271 4.19e-8 SMART
low complexity region 1282 1296 N/A INTRINSIC
Predicted Effect noncoding transcript
Transcript: ENSMUST00000199291
Predicted Effect probably benign
Transcript: ENSMUST00000200340
SMART Domains Protein: ENSMUSP00000142909
Gene: ENSMUSG00000063681

DomainStartEndE-ValueType
EGF_CA 12 49 5.15e-8 SMART
EGF 54 88 1.47e1 SMART
Meta Mutation Damage Score 0.0644 question?
Coding Region Coverage
  • 1x: 82.5%
  • 3x: 74.9%
  • 10x: 52.3%
  • 20x: 31.8%
Validation Efficiency 59% (51/87)
MGI Phenotype Strain: 3052072; 2676366
FUNCTION: [Summary is not available for the mouse gene. This summary is for the human ortholog.] This gene encodes a protein which is similar to the Drosophila crumbs protein and localizes to the inner segment of mammalian photoreceptors. In Drosophila crumbs localizes to the stalk of the fly photoreceptor and may be a component of the molecular scaffold that controls proper development of polarity in the eye. Mutations in this gene are associated with a severe form of retinitis pigmentosa, RP12, and with Leber congenital amaurosis. Alternate splicing results in multiple transcript variants, some protein coding and some non-protein coding.[provided by RefSeq, Apr 2012]
PHENOTYPE: Homozygotes for a null allele show focal retinal lesions, loss of adherens junctions between photoreceptors and Muller glia cells, and light-accelerated retinal degeneration. Homozygotes for a spontaneous allele show background-sensitive retinal spotting, photoreceptor dysplasia and degeneration. [provided by MGI curators]
Allele List at MGI

All alleles(5) : Targeted(4) Spontaneous(1)
 

Other mutations in this stock
Total: 6 list
GeneRefVarChr/LocMutationPredicted EffectZygosity
Ano4 A T 10: 88,981,190 L591* probably null Het
Arhgap30 C T 1: 171,408,704 P882L probably benign Het
C030017K20Rik G T 4: 155,463,117 Het
Fam193a G T 5: 34,440,463 D535Y probably damaging Het
Hmcn1 T A 1: 150,720,689 T1799S possibly damaging Het
Il20ra A G 10: 19,759,406 E465G probably damaging Het
Other mutations in Crb1
AlleleSourceChrCoordTypePredicted EffectPPH Score
IGL00593:Crb1 APN 1 139323245 missense probably benign 0.16
IGL01591:Crb1 APN 1 139237339 missense probably damaging 1.00
IGL01644:Crb1 APN 1 139237630 nonsense probably null
IGL01769:Crb1 APN 1 139337068 missense probably damaging 1.00
IGL02172:Crb1 APN 1 139237227 missense probably damaging 1.00
IGL02294:Crb1 APN 1 139234782 missense possibly damaging 0.89
IGL02382:Crb1 APN 1 139237614 missense probably damaging 0.99
IGL02411:Crb1 APN 1 139248475 missense probably damaging 1.00
IGL03070:Crb1 APN 1 139241258 missense possibly damaging 0.79
IGL02984:Crb1 UTSW 1 139237086 frame shift probably null
IGL02988:Crb1 UTSW 1 139237086 frame shift probably null
IGL02991:Crb1 UTSW 1 139237084 frame shift probably null
IGL02991:Crb1 UTSW 1 139237086 frame shift probably null
IGL03014:Crb1 UTSW 1 139237086 frame shift probably null
IGL03050:Crb1 UTSW 1 139237086 frame shift probably null
IGL03054:Crb1 UTSW 1 139237086 frame shift probably null
IGL03055:Crb1 UTSW 1 139237086 frame shift probably null
IGL03097:Crb1 UTSW 1 139237086 frame shift probably null
IGL03098:Crb1 UTSW 1 139237086 frame shift probably null
IGL03134:Crb1 UTSW 1 139237086 frame shift probably null
IGL03138:Crb1 UTSW 1 139237086 frame shift probably null
IGL03147:Crb1 UTSW 1 139237086 frame shift probably null
R0276:Crb1 UTSW 1 139323335 missense possibly damaging 0.85
R0325:Crb1 UTSW 1 139241166 missense probably damaging 1.00
R0401:Crb1 UTSW 1 139198791 splice site probably benign
R0479:Crb1 UTSW 1 139198614 missense probably damaging 0.98
R0734:Crb1 UTSW 1 139337084 missense probably benign 0.25
R1573:Crb1 UTSW 1 139337606 missense probably damaging 1.00
R1728:Crb1 UTSW 1 139234779 missense probably benign
R1728:Crb1 UTSW 1 139237622 missense probably benign 0.00
R1728:Crb1 UTSW 1 139241138 missense probably damaging 1.00
R1728:Crb1 UTSW 1 139242995 missense probably damaging 1.00
R1728:Crb1 UTSW 1 139243417 missense probably benign 0.00
R1729:Crb1 UTSW 1 139234779 missense probably benign
R1729:Crb1 UTSW 1 139237622 missense probably benign 0.00
R1729:Crb1 UTSW 1 139241138 missense probably damaging 1.00
R1729:Crb1 UTSW 1 139242995 missense probably damaging 1.00
R1729:Crb1 UTSW 1 139243417 missense probably benign 0.00
R1730:Crb1 UTSW 1 139234779 missense probably benign
R1730:Crb1 UTSW 1 139237622 missense probably benign 0.00
R1730:Crb1 UTSW 1 139241138 missense probably damaging 1.00
R1730:Crb1 UTSW 1 139242995 missense probably damaging 1.00
R1730:Crb1 UTSW 1 139243417 missense probably benign 0.00
R1739:Crb1 UTSW 1 139234779 missense probably benign
R1739:Crb1 UTSW 1 139237622 missense probably benign 0.00
R1739:Crb1 UTSW 1 139241138 missense probably damaging 1.00
R1739:Crb1 UTSW 1 139242995 missense probably damaging 1.00
R1739:Crb1 UTSW 1 139243417 missense probably benign 0.00
R1762:Crb1 UTSW 1 139234779 missense probably benign
R1762:Crb1 UTSW 1 139237531 missense probably damaging 1.00
R1762:Crb1 UTSW 1 139237622 missense probably benign 0.00
R1762:Crb1 UTSW 1 139241138 missense probably damaging 1.00
R1762:Crb1 UTSW 1 139242995 missense probably damaging 1.00
R1762:Crb1 UTSW 1 139243417 missense probably benign 0.00
R1783:Crb1 UTSW 1 139234779 missense probably benign
R1783:Crb1 UTSW 1 139237622 missense probably benign 0.00
R1783:Crb1 UTSW 1 139241138 missense probably damaging 1.00
R1783:Crb1 UTSW 1 139242995 missense probably damaging 1.00
R1783:Crb1 UTSW 1 139243417 missense probably benign 0.00
R1784:Crb1 UTSW 1 139234779 missense probably benign
R1784:Crb1 UTSW 1 139237622 missense probably benign 0.00
R1784:Crb1 UTSW 1 139241138 missense probably damaging 1.00
R1784:Crb1 UTSW 1 139242995 missense probably damaging 1.00
R1784:Crb1 UTSW 1 139243417 missense probably benign 0.00
R1785:Crb1 UTSW 1 139234779 missense probably benign
R1785:Crb1 UTSW 1 139237622 missense probably benign 0.00
R1785:Crb1 UTSW 1 139241138 missense probably damaging 1.00
R1785:Crb1 UTSW 1 139242995 missense probably damaging 1.00
R1785:Crb1 UTSW 1 139243417 missense probably benign 0.00
R1848:Crb1 UTSW 1 139237012 missense probably damaging 0.97
R1894:Crb1 UTSW 1 139243193 missense probably benign 0.02
R2057:Crb1 UTSW 1 139314750 missense probably damaging 1.00
R2136:Crb1 UTSW 1 139337425 missense probably benign 0.03
R2140:Crb1 UTSW 1 139237012 missense probably benign 0.01
R2363:Crb1 UTSW 1 139337278 missense possibly damaging 0.89
R3605:Crb1 UTSW 1 139237339 missense probably damaging 1.00
R3817:Crb1 UTSW 1 139248097 missense probably benign
R3942:Crb1 UTSW 1 139337473 missense possibly damaging 0.49
R4272:Crb1 UTSW 1 139323311 missense probably benign 0.04
R4301:Crb1 UTSW 1 139248830 missense probably benign 0.01
R4403:Crb1 UTSW 1 139248379 missense probably benign 0.00
R4700:Crb1 UTSW 1 139198771 missense probably damaging 0.96
R4771:Crb1 UTSW 1 139328204 missense probably damaging 1.00
R4845:Crb1 UTSW 1 139243034 missense probably benign 0.06
R4867:Crb1 UTSW 1 139243014 missense probably damaging 1.00
R5159:Crb1 UTSW 1 139243018 missense probably damaging 0.99
R5270:Crb1 UTSW 1 139236864 missense probably damaging 0.97
R5347:Crb1 UTSW 1 139337371 missense probably damaging 1.00
R5513:Crb1 UTSW 1 139236821 critical splice donor site probably null
R5641:Crb1 UTSW 1 139248889 missense probably damaging 0.99
R5754:Crb1 UTSW 1 139231599 missense probably damaging 1.00
R5968:Crb1 UTSW 1 139243001 missense probably damaging 1.00
R6122:Crb1 UTSW 1 139248948 nonsense probably null
R6369:Crb1 UTSW 1 139237462 missense probably damaging 1.00
R6809:Crb1 UTSW 1 139243126 missense probably benign 0.00
X0066:Crb1 UTSW 1 139248245 missense probably benign 0.10
Protein Function and Prediction

CRB1 is a homologue to Drosophila Crumbs, a protein that establishes apico-basal polarity in ectoderm-derived epithelia (1).  Crb1 is proposed to function in cell-cell interaction and in the maintenance of cell polarity in the retina (2).  The Drosophila homologue of CRB1, crumbs, is involved in the morphogenesis of the photoreceptors of the retina (3).  Crumbs is also a part of a scaffold that controls zonula adherens assembly and defines the stalk as an apical membrane subdomain (3).

Expression/Localization

Northern blot analysis detected the CRB1 transcript in neural retina; RT-PCR detected CRB1 in adult and fetal brain (2). In situ hybridization of mouse tissues determined that Crb1 is expressed exclusively in the eye and the brain; in post-natal stages, Crb1 is strongly detected in photoreceptor cells (4).

Background

Mutations in CRB1 are associated with retinal phenotypes (Table 1).

 

Table 1.  Phenotypes associated with mutations in CRB1.

Phenotype

MIM Number

Description

Refs

Leber congenital amaurosis 8

613835

Early-onset childhood retinal dystrophies characterized by vision loss, nystagmus, and severe retinal dysfunction

(5;6)

Pigmented paravenous chorioretinal atrophy

172870

Stationary disease of the ocular fundus in which bone corpuscle pigmentation is seen in a paravenous distribution; patients are usually asymptomatic

(7)

Retinitis pigmentosa-12, autosomal recessive

600105

Progressive retinal degeneration; symptoms include night blindness, the development of tunnel vision, slowly progressive decreased central vision starting at approximately 20 years of age, decreased visual acuity, constricted visual fields, dyschromatopsia, and dark pigmentary clumps in the midperiphery and perivenous areas ('bone spicules'), attenuated retinal vessels, cystoid macular edema, fine pigmented vitreous cells, and waxy optic disc pallor

(2)

Crb1tm1Wij/tm1Wij; MGI: 3052072

involves: 129P2/OlaHsd * C57BL/6

In homozygotes, light exposure accelerates retinal degeneration (8).  Retinal degeneration is observable by 3 months (8).  Also, photoreceptor cells form half rosettes and double layers that rupture outer membrane layer and protrude into interphotoreceptor space (8).

 

Crb1rd8/rd8; MGI:2676366

STOCK Crb1rd8/J

Homozygous mice have irregularly shaped spots concentrated in the inferior nasal quadrant of the fundus as early as week 3 that correspond to retinal folds and pseudorosettes, retinal thinning, abnormal Muller cell morphology, breakdown of the photoreceptor lamellae, decreased photoreceptor cell number, swelling and disorder of the photoreceptor inner segments, and degeneration of the photoreceptor outer segments by week 10 (9).

 

Crb1rd8/rd8; MGI:2676366

involves: C57BL/6N

Homozygotes in this genetic background have retinal pigment epithelium vacuolation, retinal lesions and spots, and diffuse lesions by 6 weeks (10).

 

Crb1rd8/rd8; MGI:2676366

B6.Cg-Crb1rd8

In this genetic background, mice do not display the spotting phenotype when backcrossed from a CAST/EiJ background onto a C57BL/6 background (9).

 

Crb1rd8/rd8; MGI:2676366

involves: C3HfB6/Ga * C57BL/6 * CAST/EiJ

In this genetic background, 19% of mice do not display the spotting phenotype on a CAST/EiJ mixed background (9).

References
Posted On2012-10-29
Science WriterAnne Murray