rs45486906

chr16-23626339-C-Achr16-23626339-C-Gchr16-23626339-C-T

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP6

The NM_024675.4(PALB2):c.2645G>T(p.Cys882Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C882Y) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PALB2 NM_024675.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:1
• Conservation: PhyloP100: -0.622

Genes affected

PALB2 (HGNC:26144): (partner and localizer of BRCA2) This gene encodes a protein that may function in tumor suppression. This protein binds to and colocalizes with the breast cancer 2 early onset protein (BRCA2) in nuclear foci and likely permits the stable intranuclear localization and accumulation of BRCA2. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.036072552).
• BP6: Variant 16-23626339-C-A is Benign according to our data. Variant chr16-23626339-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 581150.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=2, Likely_benign=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PALB2	NM_024675.4	c.2645G>T	p.Cys882Phe	missense_variant	7/13	ENST00000261584.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PALB2	ENST00000261584.9	c.2645G>T	p.Cys882Phe	missense_variant	7/13	1	NM_024675.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Nov 14, 2019	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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jan 30, 2020	This missense variant replaces cysteine with phenylalanine at codon 882 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). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. 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 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

May 20, 2018

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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The phenylalanine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with PALB2-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces cysteine with phenylalanine at codon 882 of the PALB2 protein (p.Cys882Phe). The cysteine residue is moderately conserved and there is a large physicochemical difference between cysteine and phenylalanine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.078
BayesDel_addAF	Benign	-0.32	T
BayesDel_noAF	Benign	-0.69
Cadd	Benign	0.72
Dann	Benign	0.78
DEOGEN2	Benign	0.0059	T;T
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.019	N
LIST_S2	Benign	0.39	T;T
M_CAP	Benign	0.0047	T
MetaRNN	Benign	0.036	T;T
MetaSVM	Benign	-1.1	T
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.31	T
PROVEAN	Benign	-0.51	N;N
Sift	Benign	0.89	T;T
Sift4G	Benign	0.81	T;T
Polyphen		0.0	.;B
Vest4		0.19
MutPred		0.32		.;Gain of sheet (P = 0.0827);
MVP		0.22
MPC		0.074
ClinPred		0.041	T
GERP RS		-3.3
Varity_R		0.054
gMVP		0.29

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs45486906; hg19: chr16-23637660;