rs62625283
Variant summary
Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PP3_Moderate
The NM_024675.4(PALB2):c.3418T>G(p.Trp1140Gly) variant causes a missense change. The variant allele was found at a frequency of 0.00000616 in 1,461,890 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).
Frequency
Consequence
NM_024675.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 2 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome AF: 0.00000616 AC: 9AN: 1461890Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2AN XY: 727244
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Familial cancer of breast Uncertain:3
This sequence change replaces tryptophan, which is neutral and slightly polar, with glycine, which is neutral and non-polar, at codon 1140 of the PALB2 protein (p.Trp1140Gly). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with breast cancer, colon cancer and uveal melanoma (PMID: 25225577, 27978560, 32081490). ClinVar contains an entry for this variant (Variation ID: 183828). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Experimental studies have shown that this missense change affects PALB2 function (PMID: 31586400, 33139182). 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. -
Curators: Marc Tischkowitz, Arleen D. Auerbach. Submitter to LOVD: Marc Tischkowitz. -
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Hereditary cancer-predisposing syndrome Uncertain:2
The p.W1140G variant (also known as c.3418T>G) is located in exon 13 of the PALB2 gene. This alteration results from a T to G substitution at nucleotide position 3418. The tryptophan at codon 1140 is replaced by glycine, an amino acid with highly dissimilar properties. In one study, this alteration was identified in a BRCA1/BRCA2-negative French Canadian and British proband, who was diagnosed with unilateral infiltrating ductal breast carcinoma at age 32. Loss of heterozygosity analysis of tumor tissue did not show loss of the wild-type allele (Hartley T et al. Hered Cancer Clin Pract. 2014 Aug;12:19). This alteration has also been detected in a 44-year-old male with MMR-proficient colorectal cancer (Pearlman R et al. JAMA Oncol. 2017 Apr;3:464-471). Based on protein sequence alignment, this amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
This missense variant replaces tryptophan with glycine at codon 1140 of the PALB2 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). Functional studies have reported this variant to be abnormal in BRCA2 interaction and subcellular localization (PMID: 31586400), but normal in a homology-mediated DNA repair assay (PMID: 31636395). This variant has been observed in one individual each affected with early-onset breast cancer (PMID: 25225577), colorectal cancer (PMID: 27978560), breast and skin cancer (DOI: 10.1016/j.ophtha.2019.11.009). 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. -
Familial cancer of breast;C1835817:Fanconi anemia complementation group N;C3150547:Pancreatic cancer, susceptibility to, 3 Uncertain:1
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not provided Uncertain:1
Observed in individuals with colorectal cancer, breast cancer, and/or melanoma (PMID: 25225577, 27978560, 32081490); Published functional studies are inconclusive: reduced RAD51 foci formation and sensitivity to PARP inhibitor, and inconsistent homology-directed repair activity (PMID: 31586400, 31636395); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 25225577, 33195396, 27978560, 31586400, 31636395, 32209438, 32185139, 32081490, 24485656, 19609323, 20871615, 37651980, 33139182) -
Malignant tumor of breast Uncertain:1
The PALB2 p.Trp1140Gly variant was identified in the literature in a tumour sample from a patient with breast cancer (Hartley 2014). The variant was also identified in dbSNP (ID: rs62625283) as "With Uncertain significance allele", ClinVar (classified as uncertain significance by Invitae, Ambry Genetics, GeneDx and Color), and in LOVD 3.0 (1x). The variant was not identified in the following control databases: the Exome Aggregation Consortium (August 8th 2016) or the Genome Aggregation Database (Feb 27, 2017). The p.Trp1140 residue is conserved across mammals and other organisms, and 5 of 5 computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) suggest that the variant may impact the protein; however, this information is not predictive enough to assume pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In summary, based on the above information, the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at