16-23635926-G-A

Position:

• chr16-23635926-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.620C>T​(p.Pro207Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,106 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: PALB2 NM_024675.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 0.331

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=0.07552183).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PALB2	NM_024675.4	c.620C>T	p.Pro207Leu	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.620C>T	p.Pro207Leu	missense_variant	4/13	1	NM_024675.4	ENSP00000261584	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152106 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152106 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74310

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

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	Mar 23, 2019	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Mar 09, 2021	The p.P207L variant (also known as c.620C>T), located in coding exon 4 of the PALB2 gene, results from a C to T substitution at nucleotide position 620. The proline at codon 207 is replaced by leucine, an amino acid with similar properties. This alteration was observed with an allele frequency of 0.00014 in 7,051 unselected female breast cancer patients and was not observed in 11,241 female controls of Japanese ancestry (Momozawa Y et al. Nat Commun, 2018 10;9:4083). 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. -

not provided Uncertain:1

Uncertain significance, no assertion criteria provided

curation

Leiden Open Variation Database

Oct 10, 2018

Curators: Marc Tischkowitz, Arleen D. Auerbach. Submitter to LOVD: Yukihide Momozawa. -

Familial cancer of breast Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 14, 2022

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 leucine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. ClinVar contains an entry for this variant (Variation ID: 630036). This missense change has been observed in individual(s) with breast cancer (PMID: 30287823). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 207 of the PALB2 protein (p.Pro207Leu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.096
BayesDel_addAF	Benign	-0.26	T
BayesDel_noAF	Benign	-0.62
CADD	Benign	5.4
DANN	Benign	0.30
DEOGEN2	Benign	0.31	T
Eigen	Benign	-1.0
Eigen_PC	Benign	-1.0
FATHMM_MKL	Benign	0.11	N
LIST_S2	Benign	0.64	T
M_CAP	Benign	0.0082	T
MetaRNN	Benign	0.076	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.3	L
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.24	T
PROVEAN	Uncertain	-3.8	D
REVEL	Benign	0.028
Sift	Benign	0.18	T
Sift4G	Benign	0.50	T
Polyphen		0.0060	B
Vest4		0.10
MutPred		0.16		Loss of glycosylation at P207 (P = 0.0564);
MVP		0.46
MPC		0.056
ClinPred		0.075	T
GERP RS		0.018
Varity_R		0.031
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: rs515726125; hg19: chr16-23647247;