chr16-68829653-G-A

Position:

• chr16-68829653-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM5_Supporting PM2_Supporting PS4_Moderate PVS1_Strong

This summary comes from the ClinGen Evidence Repository: The c.2296-1G>A variant is a canonical splice variant predicted to result in a truncated or absent protein (PVS1_Strong, PM5_Supporting). This variant is absent in the gnomAD cohort (PM2_supporting; http://gnomad.broadinstitute.org). This variant has been reported in at least three families meeting HDGC clinical criteria (PS4_moderate; SCV000580714.3). In summary, this variant meets criteria to be classified as likely pathogenic based on the ACMG/AMP criteria applied as specified by the CDH1 Variant Curation Expert Panel (Variant Interpretation Guidelines Version 3.1): PVS1_strong, PS4_moderate, PM2_supporting, PM5_supporting. LINK:https://erepo.genome.network/evrepo/ui/classification/CA16042157/MONDO:0007648/007

• Frequency: Genomes: not found (cov: 32)
• Consequence: CDH1 NM_004360.5 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic reviewed by expert panel P:8
• Conservation: PhyloP100: 7.95

Genes affected

CDH1 (HGNC:1748): (cadherin 1) This gene encodes a classical cadherin of the cadherin superfamily. Alternative splicing results in multiple transcript variants, at least one of which encodes a preproprotein that is proteolytically processed to generate the mature glycoprotein. This calcium-dependent cell-cell adhesion protein is comprised of five extracellular cadherin repeats, a transmembrane region and a highly conserved cytoplasmic tail. Mutations in this gene are correlated with gastric, breast, colorectal, thyroid and ovarian cancer. Loss of function of this gene is thought to contribute to cancer progression by increasing proliferation, invasion, and/or metastasis. The ectodomain of this protein mediates bacterial adhesion to mammalian cells and the cytoplasmic domain is required for internalization. This gene is present in a gene cluster with other members of the cadherin family on chromosome 16. [provided by RefSeq, Nov 2015]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PVS1: For more information check the summary or visit ClinGen Evidence Repository.
• PS4: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PM5: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CDH1	NM_004360.5	c.2296-1G>A		splice_acceptor_variant		ENST00000261769.10	NP_004351.1
CDH1	NM_001317184.2	c.2113-1G>A		splice_acceptor_variant			NP_001304113.1
CDH1	NM_001317185.2	c.748-1G>A		splice_acceptor_variant			NP_001304114.1
CDH1	NM_001317186.2	c.331-1G>A		splice_acceptor_variant			NP_001304115.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CDH1	ENST00000261769.10	c.2296-1G>A		splice_acceptor_variant		1	NM_004360.5	ENSP00000261769	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:8

Revision: reviewed by expert panel

Submissions by phenotype

Hereditary diffuse gastric adenocarcinoma Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	May 10, 2023	This variant is considered pathogenic. This variant occurs within a consensus splice junction and is predicted to result in abnormal mRNA splicing of either an out-of-frame exon or an in-frame exon necessary for protein stability and/or normal function. mRNA analysis has demonstrated abnormal mRNA splicing occurs [Myriad internal data]. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Dec 18, 2015	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Apr 15, 2021	For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. Disruption of this splice site has been observed in individual(s) with hereditary diffuse gastric cancer (Invitae). ‚ÄãClinVar contains an entry for this variant (Variation ID: 371806) This variant is not present in population databases (ExAC no frequency). This sequence change affects an acceptor splice site in intron 14 of the CDH1 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 CDH1 are known to be pathogenic (PMID: 15235021, 20373070). -

not provided Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Dec 30, 2023	Canonical splice site variant predicted to result in an in-frame loss of the adjacent exon in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 15235021, 22850631, 31296550, 31871109) -
Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Oct 18, 2022	This variant disrupts a canonical splice-acceptor site and interferes with normal CDH1 mRNA splicing. This variant has not been reported in large, multi-ethnic general populations (http://gnomad.broadinstitute.org). In the published literature, the variant has been reported in an individual with breast cancer (PMID: 31871109 (2019)). The variant has also been reported in families that meet hereditary diffuse gastric cancer criteria (https://erepo.clinicalgenome.org/). Based on the available information, this variant is classified as pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Mar 24, 2021	This variant causes a G to A nucleotide substitution at the -1 position of intron 14 of the CDH1 gene. Splice site prediction tools predict that this variant may have a significant impact on RNA splicing. To our knowledge, RNA functional studies have not been reported for this variant. This variant has been reported in individuals affected with early-onset breast cancer (PMID: 31871109) and hereditary diffuse gastric cancer (PMID: 31296550, Color internal data). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of CDH1 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Oct 14, 2019	The c.2296-1G>A intronic pathogenic mutation results from a G to A substitution one nucleotide upstream from coding exon 15 of the CDH1 gene. This alteration has been seen in multiple patients meeting diagnostic criteria for hereditary diffuse gastric cancer (Ambry internal data). Using the BDGP and ESEfinder in silico models, this alteration is predicted to shift the native splice acceptor site by one nucleotide, causing a translational frameshift; however, direct evidence is unavailable. Alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. As such, this alteration is classified as a disease-causing mutation. -

CDH1-related diffuse gastric and lobular breast cancer syndrome Pathogenic:1

Likely pathogenic, reviewed by expert panel

curation

ClinGen CDH1 Variant Curation Expert Panel

Aug 24, 2023

The c.2296-1G>A variant is a canonical splice variant predicted to result in a truncated or absent protein (PVS1_Strong, PM5_Supporting). This variant is absent in the gnomAD cohort (PM2_supporting; http://gnomad.broadinstitute.org). This variant has been reported in at least three families meeting HDGC clinical criteria (PS4_moderate; SCV000580714.3). In summary, this variant meets criteria to be classified as likely pathogenic based on the ACMG/AMP criteria applied as specified by the CDH1 Variant Curation Expert Panel (Variant Interpretation Guidelines Version 3.1): PVS1_strong, PS4_moderate, PM2_supporting, PM5_supporting. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.27
CADD	Pathogenic	36
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.92
FATHMM_MKL	Pathogenic	0.98	D
MutationTaster	Benign	1.0	D;D
GERP RS		4.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_AG_spliceai		1.0		Position offset: 2
DS_AL_spliceai		0.99		Position offset: 1

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

Publications

LitVar

Other links and lift over

dbSNP: rs1057517542; hg19: chr16-68863556;