ClinVar Genomic variation as it relates to human health

MAF >1%

Converted during submission to Benign.

p.Arg20Gln in exon 2 of PMS2: This variant is not expected to have clinical sign ificance because it has been identified in 7.8% (9003/115162) of total chromosom es by the Exome Aggregation Consortium (ExAC), including 410 homozygous individu als (http://exac.broadinstitute.org; dbSNP rs10254120). Furthermore, it was clas sified as benign on Sep. 5, 2013 by the ClinGen-approved InSiGHT expert panel (C linVar SCV000108372.2).

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 benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease.

This variant is associated with the following publications: (PMID: 28932927, 24728327, 26811195, 27153395, 7704024, 27884173, 8072530, 18768816, 24689082, 24618965, 22949387, 21239990, 23981578, 22703879)

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.

PMS2, EXON 2, c.59G>A, p.Arg20Gln, Benign (ACMG 5) In the (8072530_Nicolaides_1994, 16472587_Hendriks_2006 , 18768816_Marionvic-Terzic_2008 21239990_Pastrello_2011 , 22703879_Johnston_2012 , 23709753_Borras_2013 23981578_Wang_2013, 24618965_Dewey_2014, 24689082_Hansen_2014, 24728327_Bodian_2014, 22949387_Thompson_2013) articles, a total of 8 proband alleles of 112 (frequency: 0.027) tested positive for the variant and of the controls a total of 31 alleles of 379 tested positive (frequency: 0.082). In 22703879_johnston_2012, the variant was found in 77 of 572 individuals not included in the previous numbers; many of the articles suggest that the variant is a polymorphism and is benign. The variant was also identified in dbSNP (ID: rs10254120 ) “With untested allele”, with a minor allele frequency of 7.024% (1000 Genomes Project), HGMD, MutDB, “Mismatch Repair Genes Variant Database”, “MMR Gene Unclassified Variants Database”, “InSiGHT Colon Cancer Database”, ClinVar database. In the ClinVar database, 5 separate submitters classify the variant as benign. This variant was identified in the 1000 Genomes Project in 153 of 2178 chromosomes (frequency: 0.07), Exome Variant Server project in 272 of 4320 European American (frequency: 0.06) and in 246 of 2714 African American alleles (frequency: 0.09), increasing the likelihood that this is/may be a low frequency benign variant in certain populations of origin. The p.Arg20 residue is not conserved in mammals and the variant amino acid Glycine (Gly) is present in Trichoplax adhaerens, increasing the likelihood that this variant does not have clinical significance. Computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein and this information is not very predictive of pathogenicity. The c.59G>A variant occurs outside of the splicing consensus sequence and in silico or computational prediction software (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) does not predict a difference in splicing in 5 of 5 different programs. (However, this information is not predictive enough to rule out pathogenicity.) In summary, based on the above information, this variant meets our laboratory's criteria to be classified as benign.