1-197427616-G-C

Variant names:

• chr1-197427616-G-C
• rs375040930
• NM_201253.3:c.2291G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1 PM2 PM5 PP2

The NM_201253.3(CRB1):​c.2291G>C​(p.Arg764Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,740 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R764H) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CRB1 NM_201253.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.283
• Publications: 0 publications found

Genes affected

CRB1 (HGNC:2343): (crumbs cell polarity complex component 1) 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]

CRB1 Gene-Disease associations (from GenCC):

• hereditary macular dystrophy

  Inheritance: AR Classification: DEFINITIVE Submitted by: G2P
• Leber congenital amaurosis 8

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine
• retinitis pigmentosa 12

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• Leber congenital amaurosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• nanophthalmia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• pigmented paravenous retinochoroidal atrophy

  Inheritance: AD Classification: SUPPORTIVE, LIMITED Submitted by: G2P, Orphanet
• retinitis pigmentosa

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 15 uncertain in NM_201253.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-197427616-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 166958.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 168 curated pathogenic missense variants (we use a threshold of 10). The gene has 18 curated benign missense variants. Gene score misZ: -1.2832 (below the threshold of 3.09). Trascript score misZ: 0.62189 (below the threshold of 3.09). GenCC associations: The gene is linked to Leber congenital amaurosis 8, retinitis pigmentosa 12, pigmented paravenous retinochoroidal atrophy, hereditary macular dystrophy, retinitis pigmentosa, Leber congenital amaurosis, nanophthalmia.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_201253.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CRB1	NM_201253.3	MANE Select	c.2291G>C	p.Arg764Pro	missense	Exon 7 of 12	NP_957705.1
	CRB1	NM_001257965.2		c.2084G>C	p.Arg695Pro	missense	Exon 9 of 15	NP_001244894.1
	CRB1	NM_001193640.2		c.1955G>C	p.Arg652Pro	missense	Exon 5 of 10	NP_001180569.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CRB1	ENST00000367400.8	TSL:1 MANE Select	c.2291G>C	p.Arg764Pro	missense	Exon 7 of 12	ENSP00000356370.3
	CRB1	ENST00000638467.1	TSL:1	c.2291G>C	p.Arg764Pro	missense	Exon 7 of 11	ENSP00000491102.1
	CRB1	ENST00000367399.6	TSL:1	c.1955G>C	p.Arg652Pro	missense	Exon 5 of 10	ENSP00000356369.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461740 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727168

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44692

Ashkenazi Jewish (ASJ) AF: 0.0000383 AC: 1 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53374

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111966

Other (OTH) AF: 0.00 AC: 0 AN: 60384

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.70
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Uncertain	-0.030
CADD	Benign	18
DANN	Uncertain	0.98
DEOGEN2	Benign	0.33	T
Eigen	Benign	-0.45
Eigen_PC	Benign	-0.63
FATHMM_MKL	Benign	0.14	N
LIST_S2	Uncertain	0.90	D
M_CAP	Pathogenic	0.42	D
MetaRNN	Uncertain	0.60	D
MetaSVM	Benign	-0.62	T
MutationAssessor	Uncertain	2.6	M
PhyloP100		0.28
PrimateAI	Benign	0.21	T
PROVEAN	Uncertain	-3.4	D
REVEL	Uncertain	0.48
Sift	Benign	0.078	T
Sift4G	Benign	0.27	T
Polyphen		0.99	D
Vest4		0.69
MutPred		0.68		Loss of MoRF binding (P = 0.0073)
MVP		0.82
MPC		0.24
ClinPred		0.67	D
GERP RS		1.7
Varity_R		0.52
gMVP		0.96
Mutation Taster		=22/78	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs375040930; hg19: chr1-197396746;