rs144192844
Variant summary
Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate
The NM_000059.4(BRCA2):c.1993A>G(p.Thr665Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000373 in 1,608,024 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. T665T) has been classified as Likely benign.
Frequency
Consequence
NM_000059.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -2 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
BRCA2 | ENST00000380152.8 | c.1993A>G | p.Thr665Ala | missense_variant | Exon 11 of 27 | 5 | NM_000059.4 | ENSP00000369497.3 | ||
BRCA2 | ENST00000530893.7 | c.1624A>G | p.Thr542Ala | missense_variant | Exon 11 of 27 | 1 | ENSP00000499438.2 | |||
BRCA2 | ENST00000614259.2 | n.1993A>G | non_coding_transcript_exon_variant | Exon 10 of 26 | 2 | ENSP00000506251.1 |
Frequencies
GnomAD3 genomes AF: 0.0000263 AC: 4AN: 152208Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.00000809 AC: 2AN: 247100Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 133532
GnomAD4 exome AF: 0.00000137 AC: 2AN: 1455698Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1AN XY: 723578
GnomAD4 genome AF: 0.0000263 AC: 4AN: 152326Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74488
ClinVar
Submissions by phenotype
not provided Uncertain:3
The BRCA2 c.1993A>G (p.Thr665Ala) variant has been reported in the published literature in in an individual with leukemia in a pediatric cancer study (PMID: 26580448 (2015)). This variant has also been reported to be located in a region of the BRCA2 gene that is tolerant to missense sequence changes (PMID: 31911673 (2020)). The frequency of this variant in the general population, 0.00012 (3/24846 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 predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant. -
Has not been previously published as pathogenic or benign to our knowledge; In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Also known as 2221A>G -
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Hereditary cancer-predisposing syndrome Uncertain:2Benign:1
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Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673). -
The p.T665A variant (also known as c.1993A>G), located in coding exon 10 of the BRCA2 gene, results from an A to G substitution at nucleotide position 1993. The threonine at codon 665 is replaced by alanine, an amino acid with similar properties. This amino acid position is not 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. -
not specified Uncertain:1
Variant summary: BRCA2 c.1993A>G (p.Thr665Ala) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 8.1e-06 in 247100 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, c.1993A>G has not been reported in the literature in individuals affected with Hereditary Breast And Ovarian Cancer Syndrome. It has however been reported as a VUS in at-least one individual with hypodiplpoid ALL (Zhang_2015). These report(s) do not provide unequivocal conclusions about association of the variant with Hereditary Breast And Ovarian Cancer Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Eight submitters have cited clinical-significance assessments for this variant to ClinVar after 2014 (VUS, n=7; Likely benign, n=1). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Breast-ovarian cancer, familial, susceptibility to, 2 Uncertain:1
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BRCA2-related cancer predisposition Uncertain:1
This missense variant replaces threonine with alanine at codon 665 of the BRCA2 protein. Computational prediction suggests that this variant may not impact protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with hypodiploid ALL (PMID: 26580448). This variant has been identified in 2/247100 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. -
Hereditary breast ovarian cancer syndrome Uncertain:1
This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 665 of the BRCA2 protein (p.Thr665Ala). This variant is present in population databases (rs144192844, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with BRCA2-related conditions. ClinVar contains an entry for this variant (Variation ID: 141539). 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 BRCA2 protein function with a negative predictive value of 95%. 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at