16-68808568-G-A

Variant names:

• chr16-68808568-G-A
• rs1131690808
• NM_004360.5:c.531+1G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM5_Supporting PM2_Supporting PVS1_Strong PS4_Moderate

This summary comes from the ClinGen Evidence Repository: The c.531+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 two family meeting HDGC clinical criteria (PS4_moderate; SCV000580690.3; SCV000637838.2). 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, PM2_Supporting, PS4_moderate, PM5_Supporting. LINK:https://erepo.genome.network/evrepo/ui/classification/CA396457824/MONDO:0007648/007

• Frequency: Genomes: not found (cov: 32)
• Consequence: CDH1 NM_004360.5 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic reviewed by expert panel P:5
• Conservation: PhyloP100: 8.92
• Publications: 1 publications found

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]

CDH1 Gene-Disease associations (from GenCC):

• blepharocheilodontic syndrome 1

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Ambry Genetics, Illumina, Labcorp Genetics (formerly Invitae), G2P
• CDH1-related diffuse gastric and lobular breast cancer syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, G2P
• hereditary breast carcinoma

  Inheritance: AD Classification: DEFINITIVE Submitted by: Ambry Genetics
• hereditary diffuse gastric adenocarcinoma

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet
• cleft soft palate

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• orofacial cleft 3

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• blepharocheilodontic syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial ovarian cancer

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Likely_pathogenic. The variant received 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 rank	MANE	Protein	UniProt
CDH1	NM_004360.5	c.531+1G>A		splice_donor_variant, intron_variant	Intron 4 of 15	ENST00000261769.10	NP_004351.1
CDH1	NM_001317184.2	c.531+1G>A		splice_donor_variant, intron_variant	Intron 4 of 14		NP_001304113.1
CDH1	NM_001317185.2	c.-1085+1G>A		splice_donor_variant, intron_variant	Intron 4 of 15		NP_001304114.1
CDH1	NM_001317186.2	c.-1289+1G>A		splice_donor_variant, intron_variant	Intron 4 of 14		NP_001304115.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CDH1	ENST00000261769.10	c.531+1G>A		splice_donor_variant, intron_variant	Intron 4 of 15	1	NM_004360.5	ENSP00000261769.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:5

Revision: reviewed by expert panel

Submissions by phenotype

Hereditary diffuse gastric adenocarcinoma Pathogenic:3

May 11, 2023

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: CDH1 c.531+1G>A is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Three predict the variant abolishes a canonical 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant was absent in 251178 control chromosomes (gnomAD). c.531+1G>A has been reported in the literature in an individual affected with diffuse gastric cancer and signet cell colorectal cancer who had a family history of gastric and breast cancer (Adib_2022). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 34949788). Three submitters, including an expert panel (ClinGen CDH1 Variant Curation Expert Panel), have provided clinical-significance assessments for this variant to ClinVar after 2014 and all classified the variant as pathogenic (n=1)/likely pathogenic (n=2). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Dec 15, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature in individuals with CDH1-related disease. ClinVar contains an entry for this variant (Variation ID: 428618). This variant is not present in population databases (ExAC no frequency). This sequence change affects a donor splice site in intron 4 of the CDH1 gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. 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. 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. Donor and acceptor splice site variants 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). -

Jun 09, 2023

Myriad Genetics, Inc.

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely 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. -

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

Mar 28, 2024

ClinGen CDH1 Variant Curation Expert Panel

Significance: Likely pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

The c.531+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 two family meeting HDGC clinical criteria (PS4_moderate; SCV000580690.3; SCV000637838.2). 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, PM2_Supporting, PS4_moderate, PM5_Supporting. -

Hereditary cancer-predisposing syndrome Pathogenic:1

May 29, 2020

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.531+1G>A pathogenic intronic variant results from a G to A substitution one nucleotide after coding exon 4 of the CDH1 gene. This alteration has been detected in a family meeting clinical criteria for hereditary diffuse gastric cancer (Ambry internal data). In silico splice site analysis predicts that this alteration will weaken the native splice donor site. RNA studies have demonstrated that this alteration results in abnormal splicing in the set of samples tested (Ambry internal data). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
CADD	Pathogenic	32
DANN	Uncertain	0.99
Eigen	Pathogenic	1.3
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		8.9
GERP RS		5.9
Mutation Taster		=2/98	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.99		Position offset: -1

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

Other links and lift over

dbSNP: rs1131690808; hg19: chr16-68842471; COSMIC: COSV55728459; COSMIC: COSV55728459;