16-68812188-GT-GTT

Variant names:

• chr16-68812188-G-GT
• rs1555515731
• NM_004360.5:c.1064dupT

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.1064dupT​(p.Leu355PhefsTer13) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. L355L) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CDH1 NM_004360.5 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 0.209

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 16-68812188-G-GT is Pathogenic according to our data. Variant chr16-68812188-G-GT is described in ClinVar as [Pathogenic]. Clinvar id is 859633.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CDH1	NM_004360.5	c.1064dupT	p.Leu355PhefsTer13	frameshift_variant	Exon 8 of 16	ENST00000261769.10	NP_004351.1
CDH1	NM_001317184.2	c.1064dupT	p.Leu355PhefsTer13	frameshift_variant	Exon 8 of 15		NP_001304113.1
CDH1	NM_001317185.2	c.-552dupT		5_prime_UTR_variant	Exon 8 of 16		NP_001304114.1
CDH1	NM_001317186.2	c.-756dupT		5_prime_UTR_variant	Exon 8 of 15		NP_001304115.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CDH1	ENST00000261769.10	c.1064dupT	p.Leu355PhefsTer13	frameshift_variant	Exon 8 of 16	1	NM_004360.5	ENSP00000261769.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary diffuse gastric adenocarcinoma Pathogenic:2

Jun 12, 2023

Myriad Genetics, Inc.

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered pathogenic. This variant creates a frameshift predicted to result in premature protein truncation. -

Feb 18, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 859633). This premature translational stop signal has been observed in individual(s) with diffuse gastric cancer (PMID: 15235021). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Leu355Phefs*13) 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). -

Hereditary cancer-predisposing syndrome Pathogenic:1

Feb 24, 2023

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1064dupT pathogenic mutation, located in coding exon 8 of the CDH1 gene, results from a duplication of T at nucleotide position 1064, causing a translational frameshift with a predicted alternate stop codon (p.L355Ffs*13). This alteration has been reported in an individual affected with diffuse gastric cancer (Brooks-Wilson AR et al. J Med Genet, 2004 Jul;41:508-17). This variant was reported in 1/60,466 breast cancer cases and in 0/53,461 controls (Dorling et al. N Engl J Med. 2021 02;384:428-439). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1555515731; hg19: chr16-68846091;