rs62625277
Variant summary
Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate
The NM_024675.4(PALB2):c.1987C>T(p.Arg663Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000013 in 1,461,886 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_024675.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -2 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD3 exomes AF: 0.0000119 AC: 3AN: 251402Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 135904
GnomAD4 exome AF: 0.0000130 AC: 19AN: 1461886Hom.: 0 Cov.: 33 AF XY: 0.0000138 AC XY: 10AN XY: 727244
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Familial cancer of breast Uncertain:4Benign:1
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This variant was classified as: Uncertain significance. -
This variant is considered likely benign. This variant is strongly associated with less severe personal and family histories of cancer, typical for individuals without pathogenic variants in this gene [PMID: 25085752]. -
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This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 663 of the PALB2 protein (p.Arg663Cys). This variant is present in population databases (rs62625277, gnomAD 0.006%). This missense change has been observed in individual(s) with colorectal cancer, breast and/or ovarian cancer (PMID: 26898890, 28135145, 28825143, 34196900). ClinVar contains an entry for this variant (Variation ID: 128125). 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 PALB2 protein function with a negative predictive value of 80%. Experimental studies have shown that this missense change does not substantially affect PALB2 function (PMID: 35853885). 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. -
not provided Uncertain:3
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Published functional studies demonstrate homology-directed repair activity similar to wildtype (Wu et al., 2022); This variant is associated with the following publications: (PMID: 26898890, 28825143, 28135145, 22941656, 35853885, 35171259) -
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Hereditary cancer-predisposing syndrome Uncertain:2
The p.R663C variant (also known as c.1987C>T), located in coding exon 5 of the PALB2 gene, results from a C to T substitution at nucleotide position 1987. The arginine at codon 663 is replaced by cysteine, an amino acid with highly dissimilar properties. This alteration, designated p.Arg663Cys, has been detected in 1 of 2279 Chinese breast cancer patients (Zhang K et al. Breast Cancer Res. Treat. 2017 Dec;166:865-873). This variant was also observed in 1/287 patients with hereditary breast and/or ovarian cancer; this patient was diagnosed with breast cancer at age 48 and had a family history of breast cancer (Caminsky NG et al. Hum. Mutat., 2016 07;37:640-52). In another study, this variant was reported in 1/60,466 breast cancer cases and in 1/53,461 controls (Dorling et al. N Engl J Med. 2021 02;384:428-439). This amino acid position is poorly 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. -
This missense variant replaces arginine with cysteine at codon 663 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 been reported in an individual affected with breast cancer (PMID: 28825143). In a breast cancer case-control study, this variant has not shown a significant association with disease (PMID: 33471991 - Leiden Open Variation Database DB-ID PALB2_010651). This variant has been identified in 3/251402 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
Variant summary: PALB2 c.1987C>T (p.Arg663Cys) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.2e-05 in 251402 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1987C>T has been reported in the literature in individuals affected with Breast Cancer (Ren_2021, Zhang_2017 and Caminsky_2016) and Rectal Cancer (Yurgelun_2017) without strong evidence for causality. These reports do not provide unequivocal conclusions about association of the variant with Breast Cancer. Co-occurrences with other pathogenic variant(s) have been reported (BRCA2 c.8537_8538del, p.E2846Gfs*22), providing supporting evidence for a benign role. At least one functional study reports experimental evidence evaluating an impact on protein function and showed no damaging effect of this variant on homology directed repair (HDR) activity (e.g. Wu_2022). Seven clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. All laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as VUS - possibly benign. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at