rs764960797

Positions:

• chr7-92234558-G-A
• chr7-92234558-G-C
• chr7-92234558-G-T

Variant summary

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

The ENST00000394505.7(KRIT1):​c.880C>T​(p.Arg294Ter) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,460,802 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: KRIT1 ENST00000394505.7 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 7.35

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]

ACMG classification

Verdict is Pathogenic. Variant got 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 7-92234558-G-A is Pathogenic according to our data. Variant chr7-92234558-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 590759.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr7-92234558-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KRIT1	NM_194454.3	c.880C>T	p.Arg294Ter	stop_gained	10/19	ENST00000394505.7	NP_919436.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KRIT1	ENST00000394505.7	c.880C>T	p.Arg294Ter	stop_gained	10/19	1	NM_194454.3	ENSP00000378013	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251360 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135878

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1460802 Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 2 AN XY: 726816

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Dec 16, 2022	Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed at a significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 30161288, 31254430, 34426522, 31589614, 24466005, 23595507) -
Pathogenic, criteria provided, single submitter	clinical testing	PreventionGenetics, part of Exact Sciences	Apr 30, 2018	- -

Cerebral cavernous malformation Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Sep 20, 2021	This variant is present in population databases (rs764960797, ExAC 0.009%). This sequence change creates a premature translational stop signal (p.Arg294*) in the KRIT1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in KRIT1 are known to be pathogenic (PMID: 10508515, 11222804, 12404106, 24689081). This premature translational stop signal has been observed in individual(s) with cerebral cavernous malformations (PMID: 23595507, 31254430). For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 590759). -
Pathogenic, criteria provided, single submitter	clinical testing	Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen	Oct 15, 2024	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.63
CADD	Pathogenic	39
DANN	Uncertain	1.0
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Pathogenic	0.98	D
MutationTaster	Benign	1.0	A;A;A;A;D
Vest4		0.85
GERP RS		4.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.15		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: rs764960797; hg19: chr7-91863872; COSMIC: COSV105901161; COSMIC: COSV105901161;