NM_007294.4:c.548-3T>C
Variant summary
Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6
The NM_007294.4(BRCA1):c.548-3T>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,612,436 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 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_007294.4 splice_region, intron
Scores
Clinical Significance
Conservation
Publications
- breast-ovarian cancer, familial, susceptibility to, 1Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
- Fanconi anemia, complementation group SInheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
- pancreatic cancer, susceptibility to, 4Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
- hereditary breast ovarian cancer syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- Fanconi anemiaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Likely_benign. The variant received -3 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| BRCA1 | NM_007294.4 | c.548-3T>C | splice_region_variant, intron_variant | Intron 7 of 22 | ENST00000357654.9 | NP_009225.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| BRCA1 | ENST00000357654.9 | c.548-3T>C | splice_region_variant, intron_variant | Intron 7 of 22 | 1 | NM_007294.4 | ENSP00000350283.3 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152158Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000399 AC: 1AN: 250806 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.00000548 AC: 8AN: 1460278Hom.: 0 Cov.: 30 AF XY: 0.00000826 AC XY: 6AN XY: 726476 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152158Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74342 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:2Benign: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:2
This variant is denoted BRCA1 c.548-3T>C or IVS7-3T>C and consists of a T>C nucleotide substitution at the -3 position of intron 7 of the BRCA1 gene. Using alternate nomenclature, this variant would be defined as BRCA1 667-3T>C. In silico models are inconclusive with respect to splicing, and in the absence of RNA or functional studies, the actual effect of this variant is unknown. This variant has not, to our knowledge, been published in the literature as pathogenic or benign. BRCA1 c.548-3T>C was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, suggesting it is not a common benign variant in these populations. The thymine (T) nucleotide that is altered is not conserved across species. Based on currently available evidence, it is unclear whether BRCA1 c.548-3T>C is pathogenic or benign. We consider it to be a variant of uncertain significance.
To the best of our knowledge, the variant has not been reported in the published literature. The frequency of this variant in the general population, 0.000004 (1/250806 chromosomes, http://gnomad.broadinstitute.org), is uninformative in assessment of its pathogenicity. Analysis of this variant using software algorithms for the prediction of the effect of nucleotide changes on splicing yielded predictions that this variant does not affect BRCA1 mRNA splicing . Based on the available information, we are unable to determine the clinical significance of this variant.
Hereditary cancer-predisposing syndrome Benign:2
This alteration is classified as likely 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.
Hereditary breast ovarian cancer syndrome Uncertain:1
This sequence change falls in intron 7 of the BRCA1 gene. It does not directly change the encoded amino acid sequence of the BRCA1 protein. It affects a nucleotide within the consensus splice site. This variant is not present in population databases (gnomAD no frequency). 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: 37677). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. 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