ClinVar Genomic variation as it relates to human health

MAF >1% & Multifactorial likelihood analysis posterior probability <0.001

Converted during submission to Benign.

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease.

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease.

This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Converted during submission to Benign.

The p.Gly322Asp variant has been identified in 78 out of 3532 proband chromosomes (frequency 0.022) in individuals with endometrial and colorectal cancer phenotypes, however it is also found in 69 out of 2790 control chromosomes (frequency 0.025), increasing the likelihood that this is a benign variant (Barneston 2008, Christensen 2008, Aceto 2009, Hampel 2006, Kurzawski 2006, Raptis 2005, Valentin 2011, Pastrello 2011, Sven Arnold_2009). It is listed in dbSNP database (ID#: rs4987188) with an average heterozygosity of 0.019+/-0.096 in various human populations, further suggesting the benign nature of this variant. The p.Gly322 is highly conserved in mammals and other species, however in silico computational analysis (Sift, PolyPhen and AlignGVGD) do not suggest an impact on the protein function, therefore increasing the likelihood of this variant to be benign. Although functional impact for the yeast homolog (yMSH2–G317D) have been suggeested by earlier yeast assays (Drotschmann 1999; Ellison 2001), recent studies did not implicate any functional impact associated with the p.Gly322Asp variant (Wielders 2011, Kansikas 2011, Ollila 2008). In summary, based on the above information this variant is classified as Benign.