chr16-23635243-C-T

Position:

• chr16-23635243-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_024675.4(PALB2):​c.1303G>A​(p.Val435Ile) 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 Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: PALB2 NM_024675.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 0.750

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 -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.049566984).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PALB2	NM_024675.4	c.1303G>A	p.Val435Ile	missense_variant	4/13	ENST00000261584.9	NP_078951.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PALB2	ENST00000261584.9	c.1303G>A	p.Val435Ile	missense_variant	4/13	1	NM_024675.4	ENSP00000261584	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

May 04, 2018

This variant is denoted PALB2 c.1303G>A at the cDNA level, p.Val435Ile (V435I) at the protein level, and results in the change of a Valine to an Isoleucine (GTC>ATC). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. PALB2 Val435Ile was not observed in large population cohorts (Lek 2016). This variant is located in the Chromatin-associated motif (ChAM) (Bleuyard 2012). In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function. Based on currently available evidence, it is unclear whether PALB2 Val435Ile is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 25, 2023

The p.V435I variant (also known as c.1303G>A), located in coding exon 4 of the PALB2 gene, results from a G to A substitution at nucleotide position 1303. The valine at codon 435 is replaced by isoleucine, an amino acid with highly similar properties. 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. -

Familial cancer of breast Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 27, 2022

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. 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. ClinVar contains an entry for this variant (Variation ID: 420495). This variant has not been reported in the literature in individuals affected with PALB2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 435 of the PALB2 protein (p.Val435Ile). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.079
BayesDel_addAF	Benign	-0.33	T
BayesDel_noAF	Benign	-0.70
CADD	Benign	9.9
DANN	Benign	0.86
DEOGEN2	Benign	0.017	T;T
Eigen	Benign	-0.75
Eigen_PC	Benign	-0.73
FATHMM_MKL	Benign	0.087	N
LIST_S2	Benign	0.68	T;T
M_CAP	Benign	0.0032	T
MetaRNN	Benign	0.050	T;T
MetaSVM	Benign	-0.94	T
MutationAssessor	Benign	1.4	.;L
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.28	T
PROVEAN	Benign	-0.43	N;N
REVEL	Benign	0.11
Sift	Benign	0.37	T;T
Sift4G	Benign	0.72	T;T
Polyphen		0.018	.;B
Vest4		0.091
MutPred		0.18		.;Loss of methylation at K436 (P = 0.0971);
MVP		0.39
MPC		0.050
ClinPred		0.027	T
GERP RS		-1.5
Varity_R		0.046
gMVP		0.11

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: rs1064794517; hg19: chr16-23646564;