16-23636314-C-T
Variant summary
Our verdict is Likely benign. Variant got -3 ACMG points: 0P and 3B. BP4_ModerateBP6
The NM_024675.4(PALB2):c.232G>A(p.Val78Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00018 in 1,609,794 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/21 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 -3 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000112 AC: 17AN: 151812Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.000114 AC: 28AN: 246636Hom.: 1 AF XY: 0.000142 AC XY: 19AN XY: 133496
GnomAD4 exome AF: 0.000187 AC: 272AN: 1457982Hom.: 1 Cov.: 31 AF XY: 0.000192 AC XY: 139AN XY: 725102
GnomAD4 genome AF: 0.000112 AC: 17AN: 151812Hom.: 0 Cov.: 32 AF XY: 0.0000674 AC XY: 5AN XY: 74130
ClinVar
Submissions by phenotype
not provided Uncertain:2Benign:3
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This variant is associated with the following publications: (PMID: 22241545, 23935836, 24949998, 26315354, 26564480, 26283626, 28717660, 28051113, 18302019, 26306225, 29458332, 31586400, 31636395) -
Curators: Marc Tischkowitz, Arleen D. Auerbach. Submitters to LOVD: Marc Tischkowitz, Melissa DeRycke. -
PALB2: BP4 -
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Familial cancer of breast Benign:4
This variant is considered 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]. This variant has been observed in trans with a known pathogenic variant in one or more individuals lacking clinical features consistent with gene-specific recessive disease. -
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Hereditary cancer-predisposing syndrome Benign:3
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. -
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not specified Benign:2
Variant summary: PALB2 c.232G>A (p.Val78Ile) results in a conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00012 in 257942 control chromosomes, predominantly at a frequency of 0.00024 within the Non-Finnish European subpopulation in the gnomAD database, including 1 homozygotes. The observed variant frequency within Non-Finnish European control individuals in the gnomAD database is approximately 1.5 fold of the estimated maximal expected allele frequency for a pathogenic variant in PALB2 causing Hereditary Breast And Ovarian Cancer Syndrome phenotype (0.00016), strongly suggesting that the variant is a benign polymorphism found primarily in populations of Non-Finnish European origin. c.232G>A has been reported in the literature in individuals affected with HBOC or related cancer phenotypes (example, Bhai_2021, Blanco 2013, Damiola 2015, Thompson 2015, Tischkowitz 2012, Castellanos 2017), however, with limited information (i.e. lack of co-occurrence and/or cosegregation data). Moreover, the variant has been also reported in unaffected controls in some studies (Damiola 2015, Ramus 2015). One publication, which focuses on a family that has a history of melanoma, indicates the variant of interest to not segregate with disease (Aoude 2014); i.e. multiple family members are affected with melanomas that do not carry the variant of interest, along with unaffected family members carrying the variant. At least two publications report experimental evidence evaluating an impact on protein function (Rodrigue_2019, Wiltshire_2019). These results showed no damaging effect of this variant on BRCA1 and BRCA2 interaction and Homology directed repair activity (HDR). The following publications have been ascertained in the context of this evaluation (PMID: 24949998, 34326862, 23935836, 28051113, 26564480, 26315354, 31586400, 22241545, 31636395, 26283626). 13 submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. Multiple submitters reported the variant with conflicting assessments (Likely benign, n=10, VUS, n=3). Based on the evidence outlined above, the variant was classified as likely benign. -
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PALB2-related disorder Benign:1
This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -
Breast and/or ovarian cancer Benign:1
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Malignant tumor of breast Benign:1
The PALB2 p.Val78Ile variant was identified in 5 of 6906 proband chromosomes (frequency: 0.0007) from Spanish, Australian, Danish and American individuals or families with HBOC (BRCA1/BRCA2 negative breast cancers (with/without pancreatic cancer in the family)) or familial melanoma (Tischkowitz 2012, Thompson 2015, Blanco 2013, Aoude 2014). Segregation analysis in the familial melanoma study did not show cosegregation with disease, with 2 of 4 affected members carrying the variant. The variant was also identified in dbSNP (ID: rs515726085) as “other”, ClinVar (classified as uncertain significance by GeneDx, Invitae, PALB2 database, and likely benign by Ambry Genetics and Peter MacCallum Cancer Center Study), Clinvitae (with conflicting interpretations of pathogenicity) and (LOVD 3.0 (4X); and was not identified in Cosmic, MutDB, and Zhejiang Colon Cancer Database databases. The variant was identified in control databases in 30 (1 homozygous) of 272762 chromosomes at a frequency of 0.0001 increasing the likelihood that this may be a low frequency variant in certain populations of origin (Genome Aggregation Consortium Feb 27, 2017). The p.Val78 residue is not conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood of impact to the protein; however, this information is not predictive enough to rule out pathogenicity. The variant occurs outside of the splicing consensus sequence and 1 of 5 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) predict a greater than 10% difference in splicing; this is not very predictive of pathogenicity. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time although we would lean towards a more benign role for this variant. This variant is classified as likely benign. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at