chr2-214781312-G-T
Variant summary
Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate
The NM_000465.4(BARD1):c.562C>A(p.Pro188Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,459,722 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P188S) has been classified as Likely benign.
Frequency
Consequence
NM_000465.4 missense
Scores
Clinical Significance
Conservation
Publications
- breast cancerInheritance: AD Classification: DEFINITIVE Submitted by: G2P
- hereditary breast carcinomaInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen
- familial ovarian cancerInheritance: AD Classification: LIMITED Submitted by: ClinGen
- hereditary nonpolyposis colon cancerInheritance: AD Classification: LIMITED Submitted by: ClinGen
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ACMG classification
Our verdict: Uncertain_significance. The variant received 0 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome AF: 6.85e-7 AC: 1AN: 1459722Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0AN XY: 725806 show subpopulations
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:2
This missense variant replaces proline with threonine at codon 188 of the BARD1 protein. Computational prediction suggests that this variant may not impact protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with BARD1-related disorders in the literature. This variant has not been identified 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.P188T variant (also known as c.562C>A), located in coding exon 4 of the BARD1 gene, results from a C to A substitution at nucleotide position 562. The proline at codon 188 is replaced by threonine, an amino acid with highly similar properties. This variant was not reported in population based cohorts in the following databases: Database of Single Nucleotide Polymorphisms (dbSNP), NHLBI Exome Sequencing Project (ESP), and 1000 Genomes Project. In the ESP, this variant was not observed in 6503 samples (13006 alleles) with coverage at this position. To date, this alteration has been detected with an allele frequency of approximately 0.003% (greater than 40,000 alleles tested) in our clinical cohort. Based on protein sequence alignment, this amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of p.P188T remains unclear. -
not provided Uncertain:1
This variant is denoted BARD1 c.562C>A at the cDNA level, p.Pro188Thr (P188T) at the protein level, and results in the change of a Proline to a Threonine (CCT>ACT). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. BARD1 Pro188Thr was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. Since Proline and Threonine differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. BARD1 Pro188Thr occurs at a position that is moderately conserved through mammals and is not located in a known functional domain. In addition, in silico analyses predict that this variant is unlikely to alter protein structure or function. Based on currently available information, it is unclear whether BARD1 Pro188Thr is pathogenic or benign. We consider it to be a variant of uncertain significance. -
Familial cancer of breast Uncertain:1
This sequence change replaces proline with threonine at codon 188 of the BARD1 protein (p.Pro188Thr). The proline residue is moderately conserved and there is a small physicochemical difference between proline and threonine. 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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The threonine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with BARD1-related conditions. ClinVar contains an entry for this variant (Variation ID: 182040). This variant is not present in population databases (ExAC no frequency). -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at