16-23635873-G-A

Position:

• chr16-23635873-G-A

Variant summary

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

The NM_024675.4(PALB2):​c.673C>T​(p.Pro225Ser) 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. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. P225P) has been classified as Likely benign.

• 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: 0.178

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=0.09055027).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PALB2	NM_024675.4	c.673C>T	p.Pro225Ser	missense_variant	4/13	ENST00000261584.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PALB2	ENST00000261584.9	c.673C>T	p.Pro225Ser	missense_variant	4/13	1	NM_024675.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Dec 05, 2023	This missense variant replaces proline with serine at codon 225 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). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with PALB2-related disorders 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jun 14, 2022	The p.P225S variant (also known as c.673C>T), located in coding exon 4 of the PALB2 gene, results from a C to T substitution at nucleotide position 673. The proline at codon 225 is replaced by serine, 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. -

Familial cancer of breast Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 17, 2021

This sequence change replaces proline with serine at codon 225 of the PALB2 protein (p.Pro225Ser). The proline residue is moderately conserved and there is a moderate physicochemical difference between proline and serine. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a PALB2-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). The serine amino acid residue is also 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. In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.28	T
BayesDel_noAF	Benign	-0.64
CADD	Benign	5.8
DANN	Uncertain	0.99
DEOGEN2	Benign	0.34	T
Eigen	Benign	-0.72
Eigen_PC	Benign	-0.78
FATHMM_MKL	Benign	0.083	N
LIST_S2	Benign	0.67	T
M_CAP	Benign	0.019	T
MetaRNN	Benign	0.091	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.4	L
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.25	T
PROVEAN	Uncertain	-3.7	D
REVEL	Benign	0.053
Sift	Benign	0.10	T
Sift4G	Benign	0.14	T
Polyphen		0.38	B
Vest4		0.10
MutPred		0.40		Gain of relative solvent accessibility (P = 0.0082);
MVP		0.34
MPC		0.092
ClinPred		0.14	T
GERP RS		0.79
Varity_R		0.050
gMVP		0.23

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: rs1060502749; hg19: chr16-23647194; COSMIC: COSV105056707; COSMIC: COSV105056707;