rs587782810

Positions:

• chr16-68829795-GAAGT-G

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PVS1_Moderate PM2 PP3 PP5_Very_Strong

The ENST00000261769.10(CDH1):​c.2439+5_2439+8del variant causes a splice donor, coding sequence change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: CDH1 ENST00000261769.10 splice_donor, coding_sequence
• Clinical Significance: Likely pathogenic reviewed by expert panel P:3 U:1
• Conservation: PhyloP100: 9.82

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 Pathogenic. Variant got 13 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.053982634 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Multiple lines of computational evidence support a deleterious effect 2: max_spliceai, phyloP100way_vertebrate [when was below the threshold]
• PP5: Variant 16-68829795-GAAGT-G is Pathogenic according to our data. Variant chr16-68829795-GAAGT-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 142905.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CDH1	NM_004360.5	c.2439+5_2439+8del		splice_donor_variant, coding_sequence_variant	15/16	ENST00000261769.10	NP_004351.1
CDH1	NM_001317184.2	c.2256+5_2256+8del		splice_donor_variant, coding_sequence_variant	14/15		NP_001304113.1
CDH1	NM_001317185.2	c.891+5_891+8del		splice_donor_variant, coding_sequence_variant	15/16		NP_001304114.1
CDH1	NM_001317186.2	c.474+5_474+8del		splice_donor_variant, coding_sequence_variant	14/15		NP_001304115.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CDH1	ENST00000261769.10	c.2439+5_2439+8del		splice_donor_variant, coding_sequence_variant	15/16	1	NM_004360.5	ENSP00000261769	P1

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:3 Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

Hereditary diffuse gastric adenocarcinoma Pathogenic:1 Uncertain:1

Likely pathogenic, criteria provided, single submitter	clinical testing	European Reference Network on Genetic Tumour Risk Syndromes (ERN-GENTURIS), i3s - Instituto de Investigação e Inovação em Saúde, University of Porto	Aug 01, 2022	PS3; PS4_Supporting; PM2; PP3 (PMID: 30311375) -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 15, 2020	This variant has been reported in individual(s) affected with diffuse gastric cancer, breast cancer, and/or endometrial cancer (PMID: 26072394, 29798843). ClinVar contains an entry for this variant (Variation ID: 142905). This variant is not present in population databases (ExAC no frequency). This sequence change falls in intron 15 of the CDH1 gene. It does not directly change the encoded amino acid sequence of the CDH1 protein, but it affects a nucleotide within the consensus splice site of the intron. Nucleotide substitutions within the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). 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 available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

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

Likely pathogenic, reviewed by expert panel

curation

ClinGen CDH1 Variant Curation Expert Panel

Sep 25, 2023

The NM_004360.5(CDH1): c.2439+5_2439+8del is absent in the gnomAD cohort (PM2_Supporting; http://gnomad.broadinstitute.org). This variant is predicted to affect splicing by SpliceAI and NNSPLICE (PP3). Additionally, there is an RNA assay demonstrating an abnormal out-of-frame transcript for this variant (PS3, internal laboratory contributors). This variant has also been reported in at least 2 families meeting HDGC clinical criteria (PS4_Moderate; Internal laboratory contributors). 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): PM2_Supporting, PP3, PS3, PS4_Moderate. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 05, 2019

The c.2439+5_2439+8delGTAA intronic variant is located after coding exon 15 of the CDH1 gene. This variant results from a deletion of 4 nucleotides at positions c.2439+5 to c.2439+8. This alteration was identified in a proband with diffuse gastric cancer and lobular breast cancer (van der Post RS et al. Gastroenterology. 2015 Oct;149(4):897-906.e19). This region is highly conserved through primates but not in all available vertebrate species. Internal RNA studies confirm that this alteration results in abnormal splicing in the set of samples tested (Ambry internal data). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.45		Position offset: -50
DS_DL_spliceai		1.0		Position offset: 2

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

Publications

LitVar

Other links and lift over

dbSNP: rs587782810; hg19: chr16-68863698;