16-23626382-A-G

Variant names:

• chr16-23626382-A-G
• rs1555460026
• NM_024675.4:c.2602T>C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_024675.4(PALB2):​c.2602T>C​(p.Cys868Arg) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,884 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar 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:3
• Conservation: PhyloP100: 4.27

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 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.921

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PALB2	NM_024675.4	c.2602T>C	p.Cys868Arg	missense_variant	Exon 7 of 13	ENST00000261584.9	NP_078951.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PALB2	ENST00000261584.9	c.2602T>C	p.Cys868Arg	missense_variant	Exon 7 of 13	1	NM_024675.4	ENSP00000261584.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461884 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727242

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

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Apr 09, 2024

Institute for Biomarker Research, Medical Diagnostic Laboratories, L.L.C.

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jul 07, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.C868R variant (also known as c.2602T>C), located in coding exon 7 of the PALB2 gene, results from a T to C substitution at nucleotide position 2602. The cysteine at codon 868 is replaced by arginine, an amino acid with highly dissimilar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Familial cancer of breast Uncertain:1

May 12, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 821557). 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 cysteine, which is neutral and slightly polar, with arginine, which is basic and polar, at codon 868 of the PALB2 protein (p.Cys868Arg). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.59
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.11
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.14	T;T
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Benign	0.80	T;T
M_CAP	Benign	0.075	D
MetaRNN	Pathogenic	0.92	D;D
MetaSVM	Benign	-0.52	T
MutationAssessor	Uncertain	2.6	.;M
PrimateAI	Uncertain	0.65	T
PROVEAN	Pathogenic	-8.5	D;D
REVEL	Uncertain	0.51
Sift	Pathogenic	0.0	D;D
Sift4G	Benign	0.069	T;D
Polyphen		1.0	.;D
Vest4		0.89
MutPred		0.78		.;Gain of disorder (P = 0.0154);
MVP		0.83
MPC		0.44
ClinPred		1.0	D
GERP RS		5.9
Varity_R		0.97
gMVP		0.69

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: rs1555460026; hg19: chr16-23637703;