16-23635055-A-T

Variant names:

• chr16-23635055-A-T
• NM_024675.4:c.1491T>A

Variant summary

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

The NM_024675.4(PALB2):​c.1491T>A​(p.Asn497Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,890 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 nucleotide change resulting in the same amino acid substitution has been previously reported as Likely benign in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N497S) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: PALB2 NM_024675.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.0730

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=0.04686126).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PALB2	NM_024675.4	c.1491T>A	p.Asn497Lys	missense_variant	Exon 4 of 13	ENST00000261584.9	NP_078951.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PALB2	ENST00000261584.9	c.1491T>A	p.Asn497Lys	missense_variant	Exon 4 of 13	1	NM_024675.4	ENSP00000261584.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461890 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727244

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Familial cancer of breast Uncertain:1

Oct 24, 2021

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 tolerated. This missense change has been observed in individual(s) with pancreatic cancer (PMID: 28767289). This variant is not present in population databases (ExAC no frequency). This sequence change replaces asparagine with lysine at codon 497 of the PALB2 protein (p.Asn497Lys). The asparagine residue is weakly conserved and there is a moderate physicochemical difference between asparagine and lysine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.18
BayesDel_addAF	Benign	-0.28	T
BayesDel_noAF	Benign	-0.64
CADD	Benign	8.2
DANN	Benign	0.96
DEOGEN2	Benign	0.030	T;T
Eigen	Benign	-0.78
Eigen_PC	Benign	-0.87
FATHMM_MKL	Benign	0.20	N
LIST_S2	Benign	0.42	T;T
M_CAP	Benign	0.025	T
MetaRNN	Benign	0.047	T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.4	.;L
PrimateAI	Benign	0.29	T
PROVEAN	Benign	-1.8	N;N
REVEL	Benign	0.027
Sift	Uncertain	0.015	D;D
Sift4G	Benign	0.14	T;T
Polyphen		0.39	.;B
Vest4		0.15
MutPred		0.23		.;Gain of ubiquitination at N497 (P = 4e-04);
MVP		0.26
MPC		0.085
ClinPred		0.13	T
GERP RS		-1.2
Varity_R		0.10
gMVP		0.089

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr16-23646376;