rs80357489
Variant summary
Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate
The NM_007294.4(BRCA1):c.1448T>C(p.Ile483Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000929 in 1,613,958 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. I483V) 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
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| BRCA1 | NM_007294.4 | c.1448T>C | p.Ile483Thr | missense_variant | Exon 10 of 23 | ENST00000357654.9 | NP_009225.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| BRCA1 | ENST00000357654.9 | c.1448T>C | p.Ile483Thr | missense_variant | Exon 10 of 23 | 1 | NM_007294.4 | ENSP00000350283.3 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152138Hom.: 0 Cov.: 32 show subpopulations
GnomAD4 exome AF: 0.00000889 AC: 13AN: 1461820Hom.: 0 Cov.: 34 AF XY: 0.00000825 AC XY: 6AN XY: 727204 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152138Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74304 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:3
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This missense variant replaces isoleucine with threonine at codon 483 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). To our knowledge, functional studies have not been reported for this variant. This variant has been report in a multifactorial analysis with likelihood ratios for pathogenicity based on co-occurrence with a pathogenic variant and family history of 1.0673 and 1.4557, respectively (PMID: 31131967). This variant has been identified in 1/31406 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. -
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Hereditary cancer-predisposing syndrome Uncertain:2Benign:1
This missense variant replaces isoleucine with threonine at codon 483 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). To our knowledge, functional studies have not been reported for this variant. This variant has been report in a multifactorial analysis with likelihood ratios for pathogenicity based on co-occurrence with a pathogenic variant and family history of 1.0673 and 1.4557, respectively (PMID: 31131967). This variant has been identified in 1/31406 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. -
Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673). -
The p.I483T variant (also known as c.1448T>C), located in coding exon 9 of the BRCA1 gene, results from a T to C substitution at nucleotide position 1448. The isoleucine at codon 483 is replaced by threonine, an amino acid with similar properties. This alteration was identified amongst a cohort of 3984 Chinese women with a breast cancer diagnosis undergoing BRCA1/2 genetic testing (Yao L et al. J Hum Genet, 2022 Nov;67:639-642). This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -
not provided Uncertain:1
This variant is denoted BRCA1 c.1448T>C at the cDNA level, p.Ile483Thr (I483T) at the protein level, and results in the change of an Isoleucine to a Threonine (ATA>ACA). Using alternate nomenclature, this variant would be defined as BRCA1 1567T>C. This variant has not, to our knowledge, been published in the literature as pathogenic or benign. BRCA1 Ile483Thr was not observed at a significant allele frequency in large population cohorts (Lek 2016). Since Isoleucine and Threonine differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. BRCA1 Ile483Thr is located within the DNA binding domain and a region known to interact with multiple other proteins (Narod 2004, Paul 2014). In-silico analyses, including protein predictors and evolutionary conservation, support a deleterious effect. Based on currently available evidence, it is unclear whether BRCA1 Ile483Thr is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -
Hereditary breast ovarian cancer syndrome Uncertain:1
This sequence change replaces isoleucine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 483 of the BRCA1 protein (p.Ile483Thr). This variant is present in population databases (rs80357489, gnomAD 0.007%). 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: 54255). 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 with a negative predictive value of 95%. 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