chr1-197268467-C-CT

Variant names:

• chr1-197268467-C-CT
• rs1343680080
• NM_201253.3:c.57dupT

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_201253.3(CRB1):​c.57dupT​(p.Ile20TyrfsTer10) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000206 in 1,459,316 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. I20I) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: CRB1 NM_201253.3 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8
• Conservation: PhyloP100: 4.57

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 800 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-197268467-C-CT is Pathogenic according to our data. Variant chr1-197268467-C-CT is described in ClinVar as [Likely_pathogenic]. Clinvar id is 871211.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CRB1	NM_201253.3	c.57dupT	p.Ile20TyrfsTer10	frameshift_variant	Exon 1 of 12	ENST00000367400.8	NP_957705.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CRB1	ENST00000367400.8	c.57dupT	p.Ile20TyrfsTer10	frameshift_variant	Exon 1 of 12	1	NM_201253.3	ENSP00000356370.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251236 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135782

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1459316 Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0 AN XY: 726140

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Leber congenital amaurosis 8 Pathogenic:3

Mar 24, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 11, 2023

Genome-Nilou Lab

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

-

Laboratory of Genetics in Ophthalmology, Institut Imagine

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: research

- -

Retinitis pigmentosa 12;C1868310:Pigmented paravenous retinochoroidal atrophy;C3151202:Leber congenital amaurosis 8 Pathogenic:1

Mar 27, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Inborn genetic diseases Pathogenic:1

Sep 15, 2016

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Pathogenic:1

Sep 01, 2017

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Retinitis pigmentosa 12;C3151202:Leber congenital amaurosis 8 Pathogenic:1

May 13, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 871211). This variant is also known as Leu19 ins1. This premature translational stop signal has been observed in individual(s) with Leber congenital amaurosis (PMID: 17964524). This variant is present in population databases (no rsID available, gnomAD 0.0009%). This sequence change creates a premature translational stop signal (p.Ile20Tyrfs*10) in the CRB1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CRB1 are known to be pathogenic (PMID: 10508521, 22065545, 23379534, 25412400, 26957898, 28041643, 29391521). -

Retinitis pigmentosa 12 Pathogenic:1

Apr 11, 2023

Genome-Nilou Lab

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1343680080; hg19: chr1-197237597;