13-32398149-AT-ATT
Variant summary
Our verdict is Likely benign. Variant got -1 ACMG points: 0P and 1B. BP6
The NM_000059.4(BRCA2):c.9649-6dupT variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000194 in 1,601,636 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000059.4 splice_region, intron
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -1 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
BRCA2 | ENST00000380152.8 | c.9649-13_9649-12insT | intron_variant | Intron 26 of 26 | 5 | NM_000059.4 | ENSP00000369497.3 | |||
BRCA2 | ENST00000530893.7 | c.9280-13_9280-12insT | intron_variant | Intron 26 of 26 | 1 | ENSP00000499438.2 | ||||
BRCA2 | ENST00000614259.2 | n.*1707-13_*1707-12insT | intron_variant | Intron 25 of 25 | 2 | ENSP00000506251.1 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152110Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000330 AC: 8AN: 242742Hom.: 0 AF XY: 0.0000379 AC XY: 5AN XY: 131792
GnomAD4 exome AF: 0.0000200 AC: 29AN: 1449408Hom.: 0 Cov.: 30 AF XY: 0.0000236 AC XY: 17AN XY: 721410
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152228Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74428
ClinVar
Submissions by phenotype
not provided Uncertain:2Benign:1
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This variant is associated with the following publications: (PMID: 30702160) -
The BRCA2 c.9649-6dup variant was identified in 1 of 1652 proband chromosomes (frequency: 0.0006) from individuals or families with hereditary breast and ovarian cancer and was not identified in 2068 control chromosomes from healthy individuals (Bhaskaran 2019). The variant was identified in dbSNP (rs276174929) as “with uncertain significance allele”, ClinVar (classified as likely benign by Invitae, Color and GeneDx; and as uncertain significance by BIC), LOVD 3.0 (observed 2x) and UMD-LSDB (observed 2x). The variant was identified in control databases in 8 of 242,742 chromosomes at a frequency of 0.00003 (Genome Aggregation Database Feb 27, 2017). The variant was observed in the following populations: East Asian in 1 of 18,066 chromosomes (freq: 0.00006), Finnish in 1 of 19,514 chromosomes (freq: 0.00005), European in 4 of 111,372 chromosomes (freq: 0.00004), South Asian in 1 of 29,068 chromosomes (freq: 0.00003), and Latino in 1 of 33,502 chromosomes (freq: 0.00003); it was not observed in the African, Ashkenazi Jewish or Other populations. The c.9649-6dup variant is located in the 3' splice region but does not affect the invariant -1 and -2 positions. However, positions -3 and -5 to -12 are part of the splicing consensus sequence and variants involving these positions sometimes affect splicing. This variant results in the addition of one thymine base into a polyT tract, decreasing the likelihood that this variant has clinical significance. In addition, 4 out of 4 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -
Breast-ovarian cancer, familial, susceptibility to, 2 Uncertain:1
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not specified Benign:1
Variant summary: BRCA2 c.9649-6dupT alters a non-conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Consensus agreement among computation tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 3.3e-05 in 242742 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.9649-6dupT has been reported in the literature as a VUS in at-least one individual affected with breast cancer (example, Bhaskaran_2019). 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. The following publication has been ascertained in the context of this evaluation (PMID: 30702160). ClinVar contains an entry for this variant (Variation ID: 126216). Based on the evidence outlined above, the variant was classified as likely benign. -
BRCA2-related cancer predisposition Benign:1
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Hereditary cancer-predisposing syndrome Benign:1
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Hereditary breast ovarian cancer syndrome Benign:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at