19-15191774-T-C

Variant names:

• chr19-15191774-T-C
• rs947976672
• NM_000435.3:c.773A>G

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PS1_Moderate PM1 PM2 PP3_Strong PP5_Very_Strong

The NM_000435.3(NOTCH3):​c.773A>G​(p.Tyr258Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,588 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 Likely pathogenic (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in UniProt.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: NOTCH3 NM_000435.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 6.21

Genes affected

NOTCH3 (HGNC:7883): (notch receptor 3) This gene encodes the third discovered human homologue of the Drosophilia melanogaster type I membrane protein notch. In Drosophilia, notch interaction with its cell-bound ligands (delta, serrate) establishes an intercellular signalling pathway that plays a key role in neural development. Homologues of the notch-ligands have also been identified in human, but precise interactions between these ligands and the human notch homologues remains to be determined. Mutations in NOTCH3 have been identified as the underlying cause of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PS1: Transcript NM_000435.3 (NOTCH3) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in UniProt
• PM1: In a disulfide_bond (size 15) in uniprot entity NOTC3_HUMAN there are 8 pathogenic changes around while only 1 benign (89%) in NM_000435.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992
• PP5: Variant 19-15191774-T-C is Pathogenic according to our data. Variant chr19-15191774-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 447873.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr19-15191774-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NOTCH3	NM_000435.3	c.773A>G	p.Tyr258Cys	missense_variant	Exon 5 of 33	ENST00000263388.7	NP_000426.2
NOTCH3	XM_005259924.5	c.773A>G	p.Tyr258Cys	missense_variant	Exon 5 of 32		XP_005259981.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NOTCH3	ENST00000263388.7	c.773A>G	p.Tyr258Cys	missense_variant	Exon 5 of 33	1	NM_000435.3	ENSP00000263388.1
NOTCH3	ENST00000601011.1	c.770A>G	p.Tyr257Cys	missense_variant	Exon 5 of 23	5		ENSP00000473138.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461588 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727072

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:3

Feb 20, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 258 of the NOTCH3 protein (p.Tyr258Cys). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with cerebral arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) or clinical features of this condition (PMID: 9388399, 12821764, 28710804, 32277177, 32555735; Invitae). This variant is also known as A851G. ClinVar contains an entry for this variant (Variation ID: 447873). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt NOTCH3 protein function with a positive predictive value of 95%. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Nov 16, 2022

Athena Diagnostics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has been identified in multiple unrelated individuals with CADASIL. This variant has not been reported in large, multi-ethnic general populations (http://gnomad.broadinstitute.org). This variant alters a critical location within the protein, and is expected to severely affect function and cause disease. Greater than 90% of NOTCH3 pathogenic variants associated with CADASIL involve the gain or loss of a cysteine residue within the epidermal growth factor (EGF)-like repeat domain (PMID: 32457593, 20301673). -

Nov 30, 2022

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 24844136, 35775048, 9388399, 32555735, 32277177) -

NOTCH3-related disorder Pathogenic:1

Nov 07, 2022

PreventionGenetics, part of Exact Sciences

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The NOTCH3 c.773A>G variant is predicted to result in the amino acid substitution p.Tyr258Cys. This variant has been reported in individuals with CADASIL (Joutel et al. 1997. PubMed ID: 9388399; Mukai et al. 2020. PubMed ID: 32277177; Kim et al. 2020. PubMed ID: 32555735). This variant has not been reported in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. Most CADASIL causing variants in the NOTCH3 gene result in the gain or loss of one or more cysteine residues in the extracellular domain of the protein, as seen in this patient. This patient’s variant alters a cysteine residue and is located in the extracellular EGFr-like domain six. Pathogenic variants in EGFr domains 1-6 appear to be fully penetrant and are usually associated with the classical CADASIL phenotype. However, there is variability in disease severity. Pathogenic variants in EGFr domains 7-34 have a much higher population frequency, and can predispose to a milder small-vessel disease, possibly even displaying incomplete or at least very late onset complete penetrance (OMIM #125310; Rutten et al. 2016. PubMed ID: 27844030; Rutten et al. 2019. PubMed ID: 30032161). This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.49
CADD	Pathogenic	31
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.91	D;D
Eigen	Pathogenic	0.91
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D;D
M_CAP	Pathogenic	0.68	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.9	H;.
PrimateAI	Pathogenic	0.91	D
PROVEAN	Pathogenic	-7.9	D;.
REVEL	Pathogenic	0.95
Sift	Uncertain	0.0010	D;.
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;.
Vest4		0.97
MutPred		0.95		Gain of disorder (P = 0.0084);.;
MVP		1.0
MPC		1.4
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.91
gMVP		0.97

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs947976672; hg19: chr19-15302585;