16-68801726-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_004360.5(CDH1):c.220C>G(p.Arg74Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,166 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R74Q) has been classified as Likely benign.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: CDH1 NM_004360.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.41

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 Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CDH1	NM_004360.5	c.220C>G	p.Arg74Gly	missense_variant	3/16	ENST00000261769.10
CDH1	NM_001317184.2	c.220C>G	p.Arg74Gly	missense_variant	3/15
CDH1	NM_001317185.2	c.-1396C>G		5_prime_UTR_variant	3/16
CDH1	NM_001317186.2	c.-1600C>G		5_prime_UTR_variant	3/15

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CDH1	ENST00000261769.10	c.220C>G	p.Arg74Gly	missense_variant	3/16	1	NM_004360.5	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152166 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152166 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74344

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary diffuse gastric adenocarcinoma Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jul 28, 2023

This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 74 of the CDH1 protein (p.Arg74Gly). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CDH1-related conditions. ClinVar contains an entry for this variant (Variation ID: 231058). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 27, 2023

The p.R74G variant (also known as c.220C>G), located in coding exon 3 of the CDH1 gene, results from a C to G substitution at nucleotide position 220. The arginine at codon 74 is replaced by glycine, an amino acid with dissimilar properties. This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.52
BayesDel_addAF	Uncertain	0.018	T
BayesDel_noAF	Benign	-0.21
Cadd	Benign	20
Dann	Uncertain	0.99
DEOGEN2	Benign	0.28	T;T;T;.;.
Eigen	Uncertain	0.28
Eigen_PC	Uncertain	0.25
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Uncertain	0.88	D;D;D;D;D
M_CAP	Benign	0.042	D
MetaRNN	Uncertain	0.56	D;D;D;D;D
MetaSVM	Benign	-0.68	T
MutationAssessor	Uncertain	2.6	M;.;.;.;M
MutationTaster	Benign	0.98	D;D
PrimateAI	Benign	0.31	T
PROVEAN	Uncertain	-2.8	D;.;.;.;D
REVEL	Benign	0.20
Sift	Benign	0.16	T;.;.;.;T
Sift4G	Benign	0.41	T;T;T;T;T
Polyphen		0.83	P;.;.;.;.
Vest4		0.73
MVP		0.84
MPC		0.59
ClinPred		0.92	D
GERP RS		3.3
Varity_R		0.37
gMVP		0.47

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: rs876658932; hg19: chr16-68835629;