17-43071138-G-C
Variant summary
Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2BP4_ModerateBP6
The NM_007294.4(BRCA1):c.4776C>G(p.Asn1592Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N1592S) has been classified as Likely benign.
Frequency
Consequence
NM_007294.4 missense
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 -1 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| BRCA1 | NM_007294.4 | c.4776C>G | p.Asn1592Lys | missense_variant | Exon 15 of 23 | ENST00000357654.9 | NP_009225.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| BRCA1 | ENST00000357654.9 | c.4776C>G | p.Asn1592Lys | missense_variant | Exon 15 of 23 | 1 | NM_007294.4 | ENSP00000350283.3 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD2 exomes AF: 0.0000119 AC: 3AN: 251386 AF XY: 0.0000147 show subpopulations
GnomAD4 exome AF: 0.00000342 AC: 5AN: 1461888Hom.: 0 Cov.: 33 AF XY: 0.00000550 AC XY: 4AN XY: 727246 show subpopulations
Age Distribution
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:1Benign:2
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Hereditary cancer-predisposing syndrome Uncertain:1Benign:1
The p.N1592K variant (also known as c.4776C>G), located in coding exon 14 of the BRCA1 gene, results from a C to G substitution at nucleotide position 4776. The asparagine at codon 1592 is replaced by lysine, an amino acid with similar properties. This amino acid position is poorly 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. -
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BRCA1-related cancer predisposition Uncertain:1
This missense variant replaces asparagine with lysine at codon 1592 of the BRCA1 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). A functional study has reported that this variant does not impact BRCA1 function in a mouse Brca1-deficient embryonic cell-based assays for homology-directed DNA repair and sensitivity to cisplatin and PARP inhibitor (PMID: 32546644). This variant has been detected in a breast cancer case-control meta-analysis in 0/60466 cases and 2/53461 unaffected individuals (PMID: 33471991; Leiden Open Variation Database DB-ID BRCA1_001232). A different nucleotide change resulting in the same protein missense mutation has been reported in an individual affected with breast cancer (PMID: 23289006). This variant has been identified in 3/251386 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. -
Malignant tumor of breast Uncertain:1
The BRCA1 p.Asn1592Lys variant was identified in 1 of 242 proband chromosomes (frequency: 0.004) from individuals with breast cancer (Laraqui 2013); however, control chromosomes were not evaluated in this study. The variant was identified in three individuals in the Exome Aggregation Consortium (ExAC) database with allele counts of 1/67676 European (Non-Finnish), 1/11608 Latino, and 1/16628 South Asian alleles; however, this low number of observations and low frequency is not substantive enough to determine the prevalence of the variant in the general population and its relationship to disease. The variant was not identified in any other databases searched, including: dbSNP, NHLBI Exome Sequencing Project (Exome Variant Server), HGMD, LOVD, COSMIC, ClinVar, GeneInsight VariantWire, BIC or UMD. The variant occurs outside of the splicing consensus sequence and 2 of 5 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) predict a greater than 10% difference in splicing; however, this is not very predictive of pathogenicity. The p.Asn1592 residue is not conserved in mammals and lower organisms, and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood of impact of the variant amino acid to the protein. However, this information is not predictive enough to rule out pathogenicity. 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 unknown significance. -
not specified Benign:1
Variant summary: BRCA1 c.4776C>G (p.Asn1592Lys) results in a non-conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change. The variant allele was found at a frequency of 1.2e-05 in 251386 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.4776C>G has been observed in an individual(s) affected with breast cancer (e.g, Azim_2023). These reports do not provide unequivocal conclusions about association of the variant with Hereditary Breast And Ovarian Cancer Syndrome. At least one publication reports experimental evidence evaluating an impact on protein function (Bouwman_2020). These results showed no damaging effect of this variant on ability to complement BRCA1-deficient mouse embryonic stem cells in homologous recombination DNA repair (HRR) using cisplatin and olaparib sensitivity assays and a direct GFP HRR assay. HDR assays qualify as a recognized gold standard on the basis of updated guidance provided by the ClinGen Sequence Variant Interpretation (SVI) working group. The following publications have been ascertained in the context of this evaluation (PMID: 23289006, 23697973, 32546644, 31570899, 34296289, 37731153). ClinVar contains an entry for this variant (Variation ID: 183931). Based on the evidence outlined above, the variant was classified as likely benign. -
not provided Benign:1
This variant is associated with the following publications: (PMID: 23289006) -
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