rs876658746

Description

Variant summary: The BRIP1 c.3290A>C (p.Glu1097Ala) variant involves the alteration of a non-conserved nucleotide. 4/5 in silico tools predict a benign outcome for this variant. This variant was found in 1/131630 control chromosomes at a frequency of 0.0000076, which does not exceed the estimated maximal expected allele frequency of a pathogenic BRIP1 variant (0.0000625). To our knowledge, the variant has been reported once in the literature, without strong evidence for causality. In addition, one clinical diagnostic laboratory/reputable database classified this variant as uncertain significance. Taken together, this variant is classified as VUS.

This missense variant replaces glutamic acid with alanine at codon 1097 of the BRIP1 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 1/250890 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance.

The p.E1097A variant (also known as c.3290A>C), located in coding exon 19 of the BRIP1 gene, results from an A to C substitution at nucleotide position 3290. The glutamic acid at codon 1097 is replaced by alanine, an amino acid with dissimilar properties. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.

Not observed at a significant frequency in large population cohorts (Lek 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge

This sequence change replaces glutamic acid with alanine at codon 1097 of the BRIP1 protein (p.Glu1097Ala). The glutamic acid residue is weakly conserved and there is a moderate physicochemical difference between glutamic acid and alanine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with BRIP1-related conditions. ClinVar contains an entry for this variant (Variation ID: 230751). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.