NM_194454.3:c.1255-1_1256delGTA

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_194454.3(KRIT1):c.1255-1_1256delGTA(p.Tyr419fs) variant causes a frameshift, splice acceptor, splice region, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000069 in 1,449,596 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

KRIT1
NM_194454.3 frameshift, splice_acceptor, splice_region, intron

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 9.03

Publications

1 publications found

Variant links:

Genes affected

KRIT1 (HGNC:1573): (KRIT1 ankyrin repeat containing) This gene encodes a protein containing four ankyrin repeats, a band 4.1/ezrin/radixin/moesin (FERM) domain, and multiple NPXY sequences. The encoded protein is localized in the nucleus and cytoplasm. It binds to integrin cytoplasmic domain-associated protein-1 alpha (ICAP1alpha), and plays a critical role in beta1-integrin-mediated cell proliferation. It associates with junction proteins and RAS-related protein 1A (Rap1A), which requires the encoded protein for maintaining the integrity of endothelial junctions. It is also a microtubule-associated protein and may play a role in microtubule targeting. Mutations in this gene result in cerebral cavernous malformations. Multiple alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Sep 2009]

KRIT1 Gene-Disease associations (from GenCC):

cerebral cavernous malformation 1
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Genomics England PanelApp, Ambry Genetics, Labcorp Genetics (formerly Invitae)
famililal cerebral cavernous malformations
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

KRIT1 links:

ENSG00000289027 (HGNC:):

ENSG00000289027 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 7-92222976-ATAC-A is Pathogenic according to our data. Variant chr7-92222976-ATAC-A is described in ClinVar as Pathogenic. ClinVar VariationId is 468206.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
KRIT1	NM_194454.3 link	c.1255-1_1256delGTA	p.Tyr419fs	frameshift_variant, splice_acceptor_variant, splice_region_variant, intron_variant	Exon 13 of 19	ENST00000394505.7	NP_919436.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein
KRIT1	ENST00000394505.7 link	c.1255-1_1256delGTA	p.Tyr419fs	frameshift_variant, splice_acceptor_variant, splice_region_variant, intron_variant	Exon 13 of 19	1	NM_194454.3	ENSP00000378013.2
ENSG00000289027	ENST00000692281.1 link	c.1255-1_1256delGTA	p.Tyr419fs	frameshift_variant, splice_acceptor_variant, splice_region_variant, intron_variant	Exon 13 of 26			ENSP00000510568.1
ENSG00000285953	ENST00000458493.6 link	c.1255-1_1256delGTA	p.Tyr419fs	frameshift_variant, splice_acceptor_variant, splice_region_variant, intron_variant	Exon 12 of 20	4		ENSP00000396352.2

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.90e-7

AC:

AN:

1449596

Hom.:

AF XY:

0.00000139

AC XY:

AN XY:

722022

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33234

American (AMR)

AF:

0.00

AC:

AN:

44704

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26046

East Asian (EAS)

AF:

0.00

AC:

AN:

39582

South Asian (SAS)

AF:

0.00

AC:

AN:

85984

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52576

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5738

European-Non Finnish (NFE)

AF:

9.08e-7

AC:

AN:

1101728

Other (OTH)

AF:

0.00

AC:

AN:

60004

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Cerebral cavernous malformation

Pathogenic:2

Dec 07, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant results in the deletion of part of exon 14 (c.1255-1_1256del) of the KRIT1 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in KRIT1 are known to be pathogenic (PMID: 10508515, 11222804, 12404106, 24689081). This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with cerebral cavernous malformations (PMID: 11914398, 18300272, 24689081). It has also been observed to segregate with disease in related individuals. This variant is also known as IVS13-2delATG. ClinVar contains an entry for this variant (Variation ID: 468206). For these reasons, this variant has been classified as Pathogenic. -

Aug 17, 2022

Genetics and Molecular Pathology, SA Pathology

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

KRIT1-related disorder

Pathogenic:1

Sep 27, 2023

PreventionGenetics, part of Exact Sciences

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The KRIT1 c.1255-1_1256delGTA variant is predicted to result in a deletion affecting a canonical splice site. This variant is predicted to result in an intronic in-frame deletion. This deletion of three nucleotides abolishes the consensus splice acceptor signal and is predicted to result in aberrant splicing (SpliceAI, Jaganathan K, et al. 2019. PubMed ID: 30661751). This variant has been reported multiple times to be causative for cerebral cavernous malformations (CCMs) (Verlaan et al. 2002. PubMed ID: 11914398; Stahl et al. 2008. PubMed ID: 18300272). We have also observed this deletion in several other affected patients at PreventionGenetics. This variant has not been reported in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

PhyloP100

9.0

Mutation Taster

=0/200

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.98

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.25

Position offset: -8

DS_AL_spliceai

0.98

Position offset: 2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over