ClinVar

Description

The p.Glu49X variant was identified in 6 of 3372 proband chromosomes (frequency: 0.002) from Hispanic and/or American, and Spanish individuals or families with breast and ovarian cancers (Pal 2005, Vogel 2007, de Juan Jimenez 2013); however, control chromosomes were not evaluated in these studies. In a study using splice site assays (lymphocyte reverse transcriptase PCR and/or hybrid minigene in HeLa and nontumour breast epithelial cells), the variant induced exon 3 skipping, indicating the splicing regulatory elements were altered, in agreement with the in-silico prediction model for splicing (Sanz 2010). The variant was also identified in dbSNP (ID: rs80358435) “With pathogenic allele”, but no frequency information was provided, thus the prevalence of this variant in the general population could not be determined. The p.Glu49X variant was also identified in HGMD, LOVD, COSMIC, the ClinVar database (classified as a pathogenic variant by the Sharing Clinical Reports Project, derived from Myriad reports, as pathogenic by BIC, as pathogenic by Ambry Genetics, and no classification provided by Invitae), GeneInsight VariantWire database (1X, classified as “pathogenic” by a clinical laboratory), the BIC database (20X with pathogenic clinical importance), and UMD (20X as a 5-Causal variant). The p.Glu49X variant leads to a premature stop codon at position 49 of the polypeptide, which is predicted to lead to a truncated or absent protein and loss of function. Loss of function variants of the BRCA2 gene are an established mechanism of disease in hereditary breast and ovarian cancer and is the type of variant expected to cause the disorder. In summary, based on the above information, this variant is classified as pathogenic.