16-23629222-T-G
Variant summary
Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2BP4_Strong
The NM_024675.4(PALB2):c.2568A>C(p.Gln856His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,194 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 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. Q856K) 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
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| PALB2 | NM_024675.4 | c.2568A>C | p.Gln856His | missense_variant | Exon 6 of 13 | ENST00000261584.9 | NP_078951.2 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| PALB2 | ENST00000261584.9 | c.2568A>C | p.Gln856His | missense_variant | Exon 6 of 13 | 1 | NM_024675.4 | ENSP00000261584.4 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152194Hom.: 0 Cov.: 32 show subpopulations
GnomAD4 exome Cov.: 31
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152194Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74364 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:3
The PALB2 c.2568A>C; p.Gln856His variant (rs587781708), to our knowledge, is not reported in the medical literature but is reported in ClinVar (Variation ID: 141385). This variant is absent from the Genome Aggregation Database (v2.1.1), indicating it is not a common polymorphism. Computational analyses predict that this variant is neutral (REVEL: 0.034). Due to limited information, the clinical significance of this variant is uncertain at this time. -
This variant is denoted PALB2 c.2568A>C at the cDNA level, p.Gln856His (Q856H) at the protein level, and results in the change of a Glutamine to a Histidine (CAA>CAC). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. PALB2 Gln856His 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 Glutamine and Histidine differ in some properties, this is considered a semi-conservative amino acid substitution. PALB2 Gln856His occurs at a position that is not conserved and is located in the first WD repeat, a region of interaction with RAD51, BRCA2 and POLH, and in the region required for POLH DNA synthesis stimulation (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 Gln856His is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -
The variant has not been reported in the published literature. The frequency of this variant in the general population, 0.0000066 (1/152194 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. -
Familial cancer of breast Uncertain:2
This sequence change replaces glutamine, which is neutral and polar, with histidine, which is basic and polar, at codon 856 of the PALB2 protein (p.Gln856His). This variant is not present in population databases (gnomAD no frequency). 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: 141385). 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. -
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Hereditary cancer-predisposing syndrome Uncertain:1
The p.Q856H variant (also known as c.2568A>C), located in coding exon 6 of the PALB2 gene, results from an A to C substitution at nucleotide position 2568. The glutamine at codon 856 is replaced by histidine, an amino acid with highly similar properties. This amino acid position is 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 this alteration remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at