NM_007294.4:c.1930T>A
Variant summary
Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4BP6
The NM_007294.4(BRCA1):c.1930T>A(p.Cys644Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,461,778 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely benign in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C644G) 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 -2 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD2 exomes AF: 0.00000399 AC: 1AN: 250856 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.00000547 AC: 8AN: 1461778Hom.: 1 Cov.: 34 AF XY: 0.00000550 AC XY: 4AN XY: 727184 show subpopulations
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:2Benign:1
This missense variant replaces cysteine with serine at codon 644 of the BRCA1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in individuals affected with breast and/or ovarian cancer (PMID: 19656164, 28111427). This variant has also been identified in 1/250856 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. -
The p.C644S variant (also known as c.1930T>A), located in coding exon 9 of the BRCA1 gene, results from a T to A substitution at nucleotide position 1930. The cysteine at codon 644 is replaced by serine, an amino acid with dissimilar properties. This alteration has been reported in 1/206 breast cancer cases and 0/171 controls in a Korean study (Seong MW et al. Clin. Genet., 2009 Aug;76:152-60) as well as in 3/7051 unselected breast cancer patients and 3/11241 controls in a Japanese study (Momozawa Y et al. Nat Commun, 2018 Oct;9:4083). This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673). -
Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:1Benign:1
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
This variant is considered likely benign. This variant been observed in trans with a known pathogenic variant in one or more individuals. Compound heterozygosity for pathogenic variants in this gene is generally assumed to result in embryonic lethality. -
Hereditary breast ovarian cancer syndrome Uncertain:1
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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt BRCA1 protein function. ClinVar contains an entry for this variant (Variation ID: 409347). This missense change has been observed in individual(s) with personal and/or family history of breast and/or ovarian cancer (PMID: 19656164, 28111427, 30287823). This variant is present in population databases (rs753521391, gnomAD 0.006%). This sequence change replaces cysteine, which is neutral and slightly polar, with serine, which is neutral and polar, at codon 644 of the BRCA1 protein (p.Cys644Ser). -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at