16-23636209-G-C

Position:

• chr16-23636209-G-C

Variant summary

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

The NM_024675.4(PALB2):​c.337C>G​(p.Pro113Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,268 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P113L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: PALB2 NM_024675.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 0.0960

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=0.044279903).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PALB2	NM_024675.4	c.337C>G	p.Pro113Ala	missense_variant	4/13	ENST00000261584.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PALB2	ENST00000261584.9	c.337C>G	p.Pro113Ala	missense_variant	4/13	1	NM_024675.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461268 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 726850

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: 0.00

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

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 alanine at codon 113 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 24, 2023	The p.P113A variant (also known as c.337C>G), located in coding exon 4 of the PALB2 gene, results from a C to G substitution at nucleotide position 337. The proline at codon 113 is replaced by alanine, an amino acid with highly similar properties. This amino acid position is conserved. 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 specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Sep 14, 2018

Variant summary: PALB2 c.337C>G (p.Pro113Ala) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant was absent in 245456 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.337C>G in individuals affected with Hereditary Breast and Ovarian Cancer and no experimental evidence demonstrating its impact on protein function have been reported. Two ClinVar submissions from clinical diagnostic laboratories (evaluation after 2014) cite the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Nov 05, 2021

Not observed at significant frequency in large population cohorts (Lek 2016); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 20871615, 19369211) -

Familial cancer of breast Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 25, 2023

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. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. ClinVar contains an entry for this variant (Variation ID: 492219). 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 proline, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 113 of the PALB2 protein (p.Pro113Ala). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.077
BayesDel_addAF	Benign	-0.31	T
BayesDel_noAF	Benign	-0.68
CADD	Benign	7.5
DANN	Benign	0.56
DEOGEN2	Benign	0.22	T
Eigen	Benign	-0.98
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.14	N
LIST_S2	Benign	0.53	T
M_CAP	Benign	0.012	T
MetaRNN	Benign	0.044	T
MetaSVM	Benign	-0.98	T
MutationAssessor	Uncertain	2.2	M
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.19	T
PROVEAN	Benign	-1.4	N
REVEL	Benign	0.019
Sift	Benign	0.38	T
Sift4G	Benign	0.37	T
Polyphen		0.21	B
Vest4		0.21
MutPred		0.22		Gain of catalytic residue at P113 (P = 0.0175);
MVP		0.18
MPC		0.088
ClinPred		0.10	T
GERP RS		-5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.023
gMVP		0.025

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: rs1352495486; hg19: chr16-23647530;