chr16-68808470-CCT-C

Position:

• chr16-68808470-CCT-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_004360.5(CDH1):​c.438_439del​(p.Pro147TrpfsTer20) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,818 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CDH1 NM_004360.5 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:4
• Conservation: PhyloP100: 0.0150

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 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 16-68808470-CCT-C is Pathogenic according to our data. Variant chr16-68808470-CCT-C is described in ClinVar as [Pathogenic]. Clinvar id is 491536.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.438_439del	p.Pro147TrpfsTer20	frameshift_variant	4/16	ENST00000261769.10	NP_004351.1
CDH1	NM_001317184.2	c.438_439del	p.Pro147TrpfsTer20	frameshift_variant	4/15		NP_001304113.1
CDH1	NM_001317185.2	c.-1178_-1177del		5_prime_UTR_variant	4/16		NP_001304114.1
CDH1	NM_001317186.2	c.-1382_-1381del		5_prime_UTR_variant	4/15		NP_001304115.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CDH1	ENST00000261769.10	c.438_439del	p.Pro147TrpfsTer20	frameshift_variant	4/16	1	NM_004360.5	ENSP00000261769	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461818 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 727226

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: reviewed by expert panel

Submissions by phenotype

Hereditary diffuse gastric adenocarcinoma Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Apr 26, 2021	For these reasons, this variant has been classified as Pathogenic. This variant has not been reported in the literature in individuals with CDH1-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Pro147Trpfs*20) in the CDH1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CDH1 are known to be pathogenic (PMID: 15235021, 20373070). -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Jun 08, 2023	This variant is considered pathogenic. This variant creates a frameshift predicted to result in premature protein truncation. -

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

Pathogenic, reviewed by expert panel

curation

ClinGen CDH1 Variant Curation Expert Panel

Aug 04, 2023

The c.438_439delTC p.(Pro147Trpfs*20) variant is predicted to result in a premature stop codon that leads to nonsense mediate decay (PVS1 and PM5_supporting). The variant is absent in the gnomAD cohort (PM2_supporting; http://gnomad.broadinstitute.org). Therefore, this variant meets criteria to be classified as pathogenic based on the ACMG/AMP criteria applied as specified by the CDH1 Variant Curation Expert Panel (CDH1 VCEP specifications version 3.1): PVS1, PM2_supporting, PM5_supporting. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Feb 06, 2020

This variant deletes 2 nucleotides in exon 4 of the CDH1 gene, creating a frameshift and premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. 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. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs1555515197; hg19: chr16-68842373;