chr16-23637906-A-G

Position:

• chr16-23637906-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_024675.4(PALB2):​c.155T>C​(p.Val52Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,838 control chromosomes in the GnomAD database, with no homozygous occurrence. 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)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: PALB2 NM_024675.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:7
• Conservation: PhyloP100: 1.25

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 Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.069977134).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PALB2	NM_024675.4	c.155T>C	p.Val52Ala	missense_variant	3/13	ENST00000261584.9	NP_078951.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PALB2	ENST00000261584.9	c.155T>C	p.Val52Ala	missense_variant	3/13	1	NM_024675.4	ENSP00000261584	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461838 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727224

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000413 Hom.: 0

Bravo AF: 0.00000756

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial cancer of breast Uncertain:3

Uncertain significance, no assertion criteria provided	curation	Leiden Open Variation Database	May 13, 2019	Curators: Marc Tischkowitz, Arleen D. Auerbach. Submitter to LOVD: Marc Tischkowitz. -
Uncertain significance, criteria provided, single submitter	clinical testing	MGZ Medical Genetics Center	Mar 11, 2022	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 19, 2024	This sequence change replaces valine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 52 of the PALB2 protein (p.Val52Ala). This variant is present in population databases (rs373970237, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with PALB2-related conditions. ClinVar contains an entry for this variant (Variation ID: 246458). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The alanine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect 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. -

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jan 04, 2024	This missense variant replaces valine with alanine at codon 52 of the PALB2 protein. Computational prediction suggests that this variant may not impact protein structure and function. To our knowledge, functional studies have not been performed for this variant. This variant has been detected in a breast cancer case-control meta-analysis in 0/60466 cases and 1/53461 unaffected individuals (PMID: 33471991; Leiden Open Variation Database DB-ID PALB2_010256) and in at least one individual unaffected with ovarian cancer (PMID: 24448499). This variant has been identified in 1/246252 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jul 14, 2022	The p.V52A variant (also known as c.155T>C), located in coding exon 3 of the PALB2 gene, results from a T to C substitution at nucleotide position 155. The valine at codon 52 is replaced by alanine, an amino acid with similar properties. This amino acid position is not well 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. -

Breast neoplasm Uncertain:1

Uncertain significance, no assertion criteria provided

research

CSER _CC_NCGL, University of Washington

Aug 01, 2016

Found in a 37 year old female patient having exome sequencing for an unrelated indication. No known history of breast cancer. Family history of a mother with breast ancer diagnosed at 50, a maternal grandmother who died of breast cancer at age 58 and a paternal grandmother diagnosed with breast and ovarian cancer. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Sep 26, 2023

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Not observed in any cases, but was observed in an unaffected control from an ovarian cancer study (Kanchi et al., 2014); This variant is associated with the following publications: (PMID: 24448499, 20871615, 19369211) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.088
BayesDel_addAF	Benign	-0.088	T
BayesDel_noAF	Benign	-0.36
CADD	Benign	11
DANN	Benign	0.97
DEOGEN2	Benign	0.17	T;T
Eigen	Benign	-0.91
Eigen_PC	Benign	-0.95
FATHMM_MKL	Benign	0.081	N
LIST_S2	Benign	0.54	T;T
M_CAP	Benign	0.0040	T
MetaRNN	Benign	0.070	T;T
MetaSVM	Benign	-0.98	T
MutationAssessor	Benign	1.7	L;.
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.32	T
PROVEAN	Benign	-1.9	N;.
REVEL	Benign	0.12
Sift	Benign	0.081	T;.
Sift4G	Benign	0.14	T;.
Polyphen		0.0040	B;.
Vest4		0.25
MVP		0.50
MPC		0.068
ClinPred		0.035	T
GERP RS		-0.36
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.039
gMVP		0.031

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: rs373970237; hg19: chr16-23649227;