ClinVar Genomic variation as it relates to human health

IARC class based on posterior probability from multifactorial likelihood analysis, thresholds for class as per Plon et al. 2008 (PMID: 18951446). Class 1 based on posterior probability = 0.00000349

Variant identified in a genome or exome case(s) and assessed due to predicted null impact of the variant or pathogenic assertions in the literature or databases. Disclaimer: This variant has not undergone full assessment. The following are preliminary notes: Has been reported in 2 families with female breast and ovarian cancer (Serova-Sinilnikova 1997). Has been classified as benign by Akbari 2011 (based on Myriad classification criteria), Bodian 2011 (presence in controls), Guidugli 2014 (functional assay), Lindor 2012 (posterior probability model OR). No functional impact in DNA break repair assay (Guidugli 2013). B/LB by SCRP, GeneDx, Ambry, Counsyl, Invitae; VUS by BIC in ClinVar.

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.

The BRCA2, p.Tyr3098His variant was identified in 6 of 5110 proband chromosomes (frequency: 0.001) from individuals or families with breast, ovarian and prostate cancer (Borg 2010, Edwards 2003, Gayther 1999, Serova-Sinilnikova 1997). The variant was also identified in dbSNP (ID: rs41293521) as “other”, Clinvitae database (classified as benign by ClinVar and Invitae; uncertain significance by ClinVar), ARUP Laboratories BRCA Mutations Database (classified as not pathogenic), the ClinVar database (classified as benign by ENIGMA, MMGLUM, Invitae, Ambry Genetics, SCRP; likely benign by CHEO, GeneDx, Consyl; uncertain significance by BIC), GeneInsight COGR database (classified as benign, likely benign or uncertain significance by a clinical laboratories), the BIC database (33x with unknown clinical importance). This variant was identified in the 1000 Genomes Project in 2 of 5000 chromosomes (frequency: 0.0004), the Exome Aggregation Consortium database (August 8th 2016) in 31 of 117284 chromosomes (freq. 0.0003) in the following populations: Latino in 15 of 11252 chromosomes (freq. 0.001), European in 15 of 93796 chromosomes (freq. 0.0002), African in 1 of 10290 chromosomes (freq. 0.0001), but was not seen in Asian, Finnish and other populations. In UMD the variant was identified with a co-occurring pathogenic BRCA1 and BRCA2 variants (c.3841C>T (p.Gln1281X), c.1953dup (p.Lys652GlufsX21); c.6405_6409delCTTAA (p.Asn2135LysfsX3)), increasing the likelihood that the p.Tyr3098His variant does not have clinical significance. The variant was also identified by our laboratory in two individuals with breast cancer. The p.Tyr3098 residue is not conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood of impact to the protein; however, this information is not predictive enough to rule out pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) do not predict a difference in splicing. In addition, several functional studies classified this variant as class 1 (IARC) with probability of being deleterious 1.07×10−5 (Guidugli 2013, Lindor 2012). In summary, based on the above information, this variant meets our laboratory's criteria to be classified as benign.