ClinVar

Description

The CDH1 p.Asp805Asn variant was identified in 2 of 2886 proband chromosomes (frequency: 0.0007) from individuals or families with hereditary diffuse gastric cancer or Lynch syndrome and was present in 1 of 1362 control chromosomes (frequency: 0.0007) from healthy individuals (Bodian 2014, Hansford 2015, Yurgelun 2015). The variant was also identified in dbSNP (ID: rs200894246) as "With other allele", ClinVar (classified as benign by Invitae; as likely benign by GeneDx and Ambry Genetics; as uncertain significance by four submitters). The variant was identified in control databases in 63 of 276968 chromosomes at a frequency of 0.0002 increasing the likelihood this could be a low frequency benign variant (Genome Aggregation Database Feb 27, 2017). The variant was observed in the following populations: Other in 2 of 6460 chromosomes (freq: 0.0003), Latino in 13 of 34404 chromosomes (freq: 0.0004), European in 26 of 126584 chromosomes (freq: 0.0002), Ashkenazi Jewish in 21 of 10148 chromosomes (freq: 0.002), and South Asian in 1 of 30770 chromosomes (freq: 0.00003), while the variant was not observed in the African, East Asian, and Finnish, populations. One study performed in vitro functional assay (Vogelaar 2013) and found that the variant p.Asp805Asn affects E-cadherin protein function and its subcellular localization and can be considered as a pathogenic mutation however result have no additional functional work supports this claim and more over this missense variant and similar ones in this study have been found in families without a clinical phenotype suggesting that the in vitro data does not reflect the clinical impact of the variants. The p.Asp805 residue is conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time although we would lean towards a more benign role for this variant. This variant is classified as likely benign.