NM_194454.3:c.850C>T

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_194454.3(KRIT1):​c.850C>T​(p.Arg284*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000496 in 1,612,272 control chromosomes in the GnomAD database, with no homozygous occurrence. There is a variant allele frequency bias in the population database for this variant (GnomAdExome4), which may indicate mosaicism or somatic mutations in the reference population data. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

KRIT1
NM_194454.3 stop_gained

Scores

5
1
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2

Conservation

PhyloP100: 7.76

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 7-92234588-G-A is Pathogenic according to our data. Variant chr7-92234588-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 590758.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
KRIT1NM_194454.3 linkc.850C>T p.Arg284* stop_gained Exon 10 of 19 ENST00000394505.7 NP_919436.1 O00522-1A4D1F7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KRIT1ENST00000394505.7 linkc.850C>T p.Arg284* stop_gained Exon 10 of 19 1 NM_194454.3 ENSP00000378013.2 O00522-1
ENSG00000289027ENST00000692281.1 linkc.850C>T p.Arg284* stop_gained Exon 10 of 26 ENSP00000510568.1 A0A8I5KWQ7
ENSG00000285953ENST00000458493.6 linkc.850C>T p.Arg284* stop_gained Exon 9 of 20 4 ENSP00000396352.2 C9JD81

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
152016
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000479
AC:
7
AN:
1460256
Hom.:
0
Cov.:
30
AF XY:
0.00000688
AC XY:
5
AN XY:
726594
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.0000299
AC:
1
AN:
33440
American (AMR)
AF:
0.00
AC:
0
AN:
44716
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26116
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39670
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86230
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53412
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5760
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1110564
Other (OTH)
AF:
0.00
AC:
0
AN:
60348
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000275622), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.382
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
152016
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74236
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41356
American (AMR)
AF:
0.00
AC:
0
AN:
15258
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10576
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.625
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:2
Nov 25, 2022
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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 in large population cohorts (gnomAD); Has not been previously published as pathogenic or benign to our knowledge -

Mar 20, 2017
PreventionGenetics, part of Exact Sciences
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.66
CADD
Pathogenic
41
DANN
Uncertain
1.0
Eigen
Pathogenic
0.92
Eigen_PC
Pathogenic
0.80
FATHMM_MKL
Pathogenic
0.99
D
PhyloP100
7.8
Vest4
0.86, 0.85
GERP RS
5.3
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Mutation Taster
=1/199
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.26
Details are displayed if max score is > 0.2
DS_AL_spliceai
0.26
Position offset: 4

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

Publications

Other links and lift over

dbSNP: rs374662170; hg19: chr7-91863902; COSMIC: COSV60669931; COSMIC: COSV60669931; API