Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2
The NM_007294.4(BRCA1):c.1920A>T(p.Gln640His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,613,972 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
BRCA1 (HGNC:1100): (BRCA1 DNA repair associated) This gene encodes a 190 kD nuclear phosphoprotein that plays a role in maintaining genomic stability, and it also acts as a tumor suppressor. The BRCA1 gene contains 22 exons spanning about 110 kb of DNA. The encoded protein combines with other tumor suppressors, DNA damage sensors, and signal transducers to form a large multi-subunit protein complex known as the BRCA1-associated genome surveillance complex (BASC). This gene product associates with RNA polymerase II, and through the C-terminal domain, also interacts with histone deacetylase complexes. This protein thus plays a role in transcription, DNA repair of double-stranded breaks, and recombination. Mutations in this gene are responsible for approximately 40% of inherited breast cancers and more than 80% of inherited breast and ovarian cancers. Alternative splicing plays a role in modulating the subcellular localization and physiological function of this gene. Many alternatively spliced transcript variants, some of which are disease-associated mutations, have been described for this gene, but the full-length natures of only some of these variants has been described. A related pseudogene, which is also located on chromosome 17, has been identified. [provided by RefSeq, May 2020]
University of Washington Department of Laboratory Medicine, University of Washington
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: curation
Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673). -
Jun 10, 2023
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The p.Q640H variant (also known as c.1920A>T), located in coding exon 9 of the BRCA1 gene, results from an A to T substitution at nucleotide position 1920. The glutamine at codon 640 is replaced by histidine, an amino acid with highly similar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Jun 07, 2019
Color Diagnostics, LLC DBA Color Health
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
- -
not specified Uncertain:1
Jan 11, 2021
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
Variant summary: BRCA1 c.1920A>T (p.Gln640His) 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 allele was found at a frequency of 4e-06 in 251046 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.1920A>T in individuals affected with Hereditary Breast And Ovarian Cancer Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Two 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. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:1
Apr 05, 2010
Sharing Clinical Reports Project (SCRP)
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing
- -
not provided Uncertain:1
Jul 29, 2024
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The BRCA1 c.1920A>T (p.Gln640His) variant has been reported in the published literature be located in a region of the BRCA1 gene that is tolerant to missense sequence changes (PMID: 31911673 (2020)). To the best of our knowledge, this variant has not been reported in individuals with BRCA1-related disorders. The frequency of this variant in the general population, 0.000004 (1/251046 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded conflicting predictions that this variant is benign or damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -
Hereditary breast ovarian cancer syndrome Uncertain:1
Dec 20, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This sequence change replaces glutamine, which is neutral and polar, with histidine, which is basic and polar, at codon 640 of the BRCA1 protein (p.Gln640His). This variant is present in population databases (rs587782843, gnomAD 0.007%). This variant has not been reported in the literature in individuals affected with BRCA1-related conditions. ClinVar contains an entry for this variant (Variation ID: 142950). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt BRCA1 protein function with a negative predictive value of 80%. 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. -
Fanconi anemia, complementation group S Uncertain:1
Aug 24, 2022
Department of Pathology and Laboratory Medicine, Sinai Health System
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Gain of phosphorylation at T637 (P = 0.1409);Gain of phosphorylation at T637 (P = 0.1409);.;Gain of phosphorylation at T637 (P = 0.1409);.;Gain of phosphorylation at T637 (P = 0.1409);.;