13-32363187-C-T
Variant summary
Our verdict is Likely benign. Variant got -3 ACMG points: 0P and 3B. BP4_ModerateBP6
The NM_000059.4(BRCA2):c.7985C>T(p.Thr2662Met) variant causes a missense change. The variant allele was found at a frequency of 0.0000281 in 1,460,966 control chromosomes in the GnomAD database, including 1 homozygotes. 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. T2662T) 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 -3 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
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BRCA2 | ENST00000380152.8 | c.7985C>T | p.Thr2662Met | missense_variant | Exon 18 of 27 | 5 | NM_000059.4 | ENSP00000369497.3 | ||
BRCA2 | ENST00000530893.7 | c.7616C>T | p.Thr2539Met | missense_variant | Exon 18 of 27 | 1 | ENSP00000499438.2 | |||
BRCA2 | ENST00000614259.2 | n.*43C>T | non_coding_transcript_exon_variant | Exon 17 of 26 | 2 | ENSP00000506251.1 | ||||
BRCA2 | ENST00000614259 | n.*43C>T | 3_prime_UTR_variant | Exon 17 of 25 | 2 | ENSP00000506251.1 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD3 exomes AF: 0.00000400 AC: 1AN: 250098Hom.: 0 AF XY: 0.00000739 AC XY: 1AN XY: 135322
GnomAD4 exome AF: 0.0000281 AC: 41AN: 1460966Hom.: 1 Cov.: 31 AF XY: 0.0000358 AC XY: 26AN XY: 726828
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:1Benign:2
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This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
not provided Uncertain:2
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This variant is denoted BRCA2 c.7985C>T at the cDNA level, p.Thr2662Met (T2662M) at the protein level, and results in the change of a Threonine to a Methionine (ACG>ATG). Using alternate nomenclature, this variant would be defined as BRCA2 8213C>T. In a minigene assay, BRCA2 Thr2662Met was shown to result in 3.3% of transcripts skipping exon 18, a naturally occurring isoform (Fraile-Bethencourt 2017). BRCA2 Thr2662Met was not observed at a significant allele frequency in large population cohorts (Lek 2016). This variant is located within the DNA binding domain (Yang 2002). In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function. Based on currently available information, it is unclear whether BRCA2 Thr2662Met is pathogenic or benign. We consider it to be a variant of uncertain significance. -
Hereditary breast ovarian cancer syndrome Benign:2
According to the ClinGen ENIGMA BRCA2 v1.1.0 criteria we chose these criteria: PP4 (supporting pathogenic): Combined LR Score 2.21201 (Parsons et al.), BP4 (supporting benign): BayesDel: -0.2316; spliceAI:0.01, BS3 (strong benign): Reported by one calibrated study to exhibit protein function similar to benign control variants (PMID:33609447) (BS3 met). -
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Breast-ovarian cancer, familial, susceptibility to, 2 Uncertain:1
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BRCA2-related cancer predisposition Uncertain:1
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not specified Benign:1
Variant summary: BRCA2 c.7985C>T (p.Thr2662Met) results in a non-conservative amino acid change located in the Breast cancer type 2 susceptibility protein, helical domain (IPR015252) of the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. 5/5 computational tools predict no significant impact on normal splicing, which was confirmed by one functional study (Fraile-Bethencourt_2017). The variant allele was found at a frequency of 4e-06 in 250098 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.7985C>T has been reported in the literature as a VUS in one individual who had personal or family history of breast and/or ovarian cancer (example, Tsaousis_2019) and in control cohorts (example, Dorling_2021). These report(s) does not provide unequivocal conclusions about association of the variant with Hereditary Breast and Ovarian Cancer. At-least two co-occurrences with another pathogenic variant has been reported in the UMD database and at our laboratory (UMD-BRCA1 c.5080G>T, p.Glu1694X; our laboratory-BRCA2 c.3915del, p.Phe1305fs), providing supporting evidence for a benign role. At least two publications report experimental evidence evaluating an impact on protein function demonstrating no damaging effect in a homology-directed repair (HDR) assay (example, Hart_2018, Richardson_2021). HDR assays qualify as a recognized gold standard on the basis of updated guidance provided by the ClinGen Sequence Variant Interpretation (SVI) working group. This working group has recommended strong functional evidence (ACMG BS3) as sufficient weightage for categorization as likely benign (Tavtigian_2018). Seven clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation (VUS, n=4; Likely benign/Benign, n=3). Based on the evidence outlined above, the variant was classified as benign. -
Hereditary cancer Benign:1
This variant is considered likely benign or benign based on one or more of the following: it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease, and/or has normal protein function, and/or has lack of segregation with disease, and/or has been detected in co-occurrence with known pathogenic variant, and/or has lack of disease association in case-control studies, and/or is located in a region inconsistent with a known cause of pathogenicity. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at