16-23629957-T-C
Variant summary
Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2BP4_Strong
The NM_024675.4(PALB2):c.2197A>G(p.Thr733Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,614,066 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 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. T733S) has been classified as Uncertain significance.
Frequency
Consequence
NM_024675.4 missense
Scores
Clinical Significance
Conservation
Publications
- hereditary breast carcinomaInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen, Ambry Genetics
- Fanconi anemia complementation group NInheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
- pancreatic cancer, susceptibility to, 3Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
- familial ovarian cancerInheritance: AD Classification: MODERATE Submitted by: ClinGen
- Fanconi anemiaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- hereditary nonpolyposis colon cancerInheritance: AD Classification: LIMITED Submitted by: ClinGen
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ACMG classification
Our verdict: Likely_benign. The variant received -2 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152174Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251490 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 6.84e-7 AC: 1AN: 1461892Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1AN XY: 727248 show subpopulations
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152174Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74344 show subpopulations
ClinVar
Submissions by phenotype
not provided Uncertain:2
The variant has not been reported in the published literature. The frequency of this variant in the general population, 0.000004 (1/251490 chromosomes, http://gnomad.broadinstitute.org), is uninformative in assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant. -
This variant is denoted PALB2 c.2197A>G at the cDNA level, p.Thr733Ala (T733A) at the protein level, and results in the change of a Threonine to an Alanine (ACT>GCT). This variant has not, to our knowledge, been published in the literature as either a germline pathogenic or benign variant. However, it has been reported as a somatic variant identified in a colorectal cancer cell line (Mouradov 2014). PALB2 Thr733Ala 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. Since Threonine and Alanine differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. PALB2 Thr733Ala occurs at a position that is not conserved and is not located in a known functional domain (Uniprot). In silico analyses predict that this variant is unlikely to alter protein structure or function. Based on currently available evidence, it is unclear whether PALB2 Thr733Ala is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -
Hereditary cancer-predisposing syndrome Uncertain:1Benign:1
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. -
This missense variant replaces threonine with alanine at codon 733 of the PALB2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 1/251490 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. -
not specified Uncertain:1
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Familial cancer of breast;C1835817:Fanconi anemia complementation group N;C3150547:Pancreatic cancer, susceptibility to, 3 Uncertain:1
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Familial cancer of breast Uncertain:1
This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 733 of the PALB2 protein (p.Thr733Ala). This variant is present in population databases (no rsID available, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with PALB2-related conditions. ClinVar contains an entry for this variant (Variation ID: 246024). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt PALB2 protein function with a negative predictive value of 80%. 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