ClinVar

Description

Variant summary: CDH1 c.2413G>A (p.Asp805Asn) results in a conservative amino acid change located in the Cadherin, cytoplasmic domain (IPR000233) of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00024 in 251938 control chromosomes. The observed variant frequency is approximately 9 fold of the estimated maximal expected allele frequency for a pathogenic variant in CDH1 causing Hereditary Diffuse Gastric Cancer phenotype (2.8e-05), strongly suggesting that the variant is benign. c.2413G>A has been reported in the literature in a family with gastric and diffuse gastric cancer in an unaffected patient; however the age was not provided (Hansford_2015). An additional CDH1 variant (c.2430delT) was also identified in a proband affected with DGC in this family. This variant was also observed associated with non-syndromic cleft-palate, Lynch Syndrome, pancreatic ductal adenocarcinoma, and NSCLC patients without strong evidence for causality (Vogelaar_2013, Yurgelun_2015, Yurgelun_2017, Rangachari_2015, Shindo_2017, Shirts_2016). These report(s) do not provide unequivocal conclusions about association of the variant with Hereditary Diffuse Gastric Cancer. At-least one co-occurrence with another pathogenic variant has been observed at our laboratory (BRCA2 c.7618-1G>A), providing supporting evidence for a benign role. At least one publication reports experimental evidence evaluating an impact on protein function (Vogelaar_2013). The most pronounced variant effect results in slightly impaired cell invasion suppression, displaying smaller cellular aggregates than the WT and to result in reduced membranous E-cadherin expression while not affecting the expression level of CDH1. However, the clinical relevance of these functional impacts is uncertain. Multiple clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Multiple laboratories reported the variant with conflicting assessments with a majority consensus leaning towards benign/likely benign (n=8). Based on the evidence outlined above, the variant was classified as benign.