rs786202760
Variant summary
Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP3_Strong
The NM_032043.3(BRIP1):c.1941G>T(p.Trp647Cys) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,642 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. W647G) has been classified as Uncertain significance.
Frequency
Consequence
NM_032043.3 missense
Scores
Clinical Significance
Conservation
Publications
- familial ovarian cancerInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- Fanconi anemiaInheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, Illumina
- Fanconi anemia complementation group JInheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, ClinGen, Ambry Genetics, Labcorp Genetics (formerly Invitae)
- hereditary breast carcinomaInheritance: AD Classification: STRONG, LIMITED, NO_KNOWN Submitted by: ClinGen, Genomics England PanelApp, Ambry Genetics, Labcorp Genetics (formerly Invitae)
- colorectal adenomaInheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
Genome browser will be placed here
ACMG classification
Our verdict: Likely_pathogenic. The variant received 6 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome AF: 6.84e-7 AC: 1AN: 1461642Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1AN XY: 727144 show subpopulations
Age Distribution
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Familial cancer of breast;C1836860:Fanconi anemia complementation group J Uncertain:2
- -
This sequence change replaces tryptophan, which is neutral and slightly polar, with cysteine, which is neutral and slightly polar, at codon 647 of the BRIP1 protein (p.Trp647Cys). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with breast cancer (PMID: 25981591). ClinVar contains an entry for this variant (Variation ID: 186189). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt BRIP1 protein function with a positive predictive value of 80%. Experimental studies have shown that this missense change affects BRIP1 function (PMID: 29788478). 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. -
Hereditary cancer-predisposing syndrome Uncertain:2
This missense variant replaces tryptophan with cysteine at codon 647 of the BRIP1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). A functional study has shown that this variant protein displays reduced helicase activity in an in vitro assay (PMID: 29788478). While this variant has not been reported in individuals affected with BRIP1-associated diseases in the literature, a different variant (c.1941G>C) resulting in the same amino acid change has been reported in individuals affected with Fanconi anemia and breast cancer (PMID: 16116423, 25981591). This variant has not been identified 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.W647C variant (also known as c.1941G>T), located in coding exon 13 of the BRIP1 gene, results from a G to T substitution at nucleotide position 1941. The tryptophan at codon 647 is replaced by cysteine, an amino acid with highly dissimilar properties. Functional assays indicate this alteration inactivates the helicase activity of the protein, and severely compromises its ability to hydrolyze ATP (Bharti SK et al. Nucleic Acids Res., 2018 Jul;46:6238-6256). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -
Familial cancer of breast Uncertain:2
This variant is classified as a variant of uncertain significance as there is insufficient evidence to determine its impact on protein function and/or cancer risk. -
- -
not specified Uncertain:1
Variant summary: BRIP1 c.1941G>T (p.Trp647Cys) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 251268 control chromosomes. c.1941G>T has been reported in the literature as a VUS in settings of multigene panel testing in at-least two individuals affected with high-risk features for hereditary breast and ovarian cancer (HBOC) and with a previous uninformative result for BRCA1/2 (Fonfria_2021). One of these individuals reported a triple negative subtype (ER/PR/HER2), while the other reported a triple positive subtype of breast cancer. Furthermore, a different nucleotide substitution, c.1941G>C, that results in an identical amino acid substitution, namely p.Trp647Cys, has been identified along with another FANCJ (BRIP1) allele in an individual affected with Fanconi Anemia (Levitus_2005). Another study reported this specific nucleotide variant in controls but not in breast cancer cases (Weber-Lassalle_2018). Some reports do not specify the exact nucleotide alteration and limit reporting to the affected protein (example, Guo_2016, Bharti_2018 described below). Therefore, these report(s) do not provide unequivocal conclusions about association of the variant with Hereditary Breast And Ovarian Cancer Syndrome. At least one publication reports experimental evidence evaluating an impact on protein function (Bharti_2018). The most pronounced variant effect results in <10% of normal helicase activity as evidenced by a decrease in Kcat for ATP hydrolysis in a recombinant FANCJ protein expressing baculovirus system. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Some submitters cite overlapping evidence utilized in the context of this evaluation. Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -
Ovarian cancer Uncertain:1
This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
Fanconi anemia complementation group J Uncertain:1
This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
not provided Uncertain:1
Observed in individuals with breast cancer (Fonfria 2021); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Another substitution, BRIP1 1941G>C, resulting in the same Trp647Cys missense variant has been observed in at least one individual with breast cancer and has been co-observed with a second BRIP1 variant, phase unknown, in an individual with Fanconi anemia (Levitus 2005, Lajus 2015). Furthermore BRIP1 1941G>C (Trp647Cys) has been associated with absent helicase activity and reduced ATP hydrolysis (Bharti 2018).; This variant is associated with the following publications: (PMID: 16116423, 29368626, 23276657, 17145708, 29788478, 25981591, 34204722) -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at