16-23635324-A-C

Variant names:

• chr16-23635324-A-C
• rs515726064
• NM_024675.4:c.1222T>G

Variant summary

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

The NM_024675.4(PALB2):​c.1222T>G​(p.Tyr408Asp) variant causes a missense change. The variant allele was found at a frequency of 0.00000342 in 1,461,780 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: 0.0000034 (0 hom.)
• Consequence: PALB2 NM_024675.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 6.34

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, 0.85

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PALB2	NM_024675.4	c.1222T>G	p.Tyr408Asp	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.1222T>G	p.Tyr408Asp	missense_variant	Exon 4 of 13	1	NM_024675.4	ENSP00000261584.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461780 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727190

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000101

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: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Aug 07, 2018

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 03, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Y408D variant (also known as c.1222T>G), located in coding exon 4 of the PALB2 gene, results from a T to G substitution at nucleotide position 1222. The tyrosine at codon 408 is replaced by aspartic acid, an amino acid with highly dissimilar properties. This alteration was observed with an allele frequency of 0.00028 in 7,051 unselected female breast cancer patients and was observed with an allele frequency of 0.0000 in 11,241 female controls of Japanese ancestry. In addition, it was observed with an allele frequency of 0.0000 in 53 unselected male breast cancer patients and was observed with an allele frequency of 0.0001 in 12,490 male controls of Japanese ancestry (Momozawa Y et al. Nat Commun, 2018 10;9:4083). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1

Oct 10, 2018

Leiden Open Variation Database

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: curation

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

Familial cancer of breast Uncertain:1

Feb 10, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces tyrosine, which is neutral and polar, with aspartic acid, which is acidic and polar, at codon 408 of the PALB2 protein (p.Tyr408Asp). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with breast cancer (PMID: 30287823). ClinVar contains an entry for this variant (Variation ID: 185091). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt PALB2 protein function with a positive predictive value of 80%. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.82
BayesDel_addAF	Pathogenic	0.28	D
BayesDel_noAF	Pathogenic	0.17
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Benign	0.21	T;D
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.77
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.84	T;T
M_CAP	Benign	0.077	D
MetaRNN	Pathogenic	0.85	D;D
MetaSVM	Benign	-0.42	T
MutationAssessor	Uncertain	2.2	.;M
PrimateAI	Uncertain	0.66	T
PROVEAN	Pathogenic	-7.5	D;D
REVEL	Uncertain	0.47
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;T
Polyphen		1.0	.;D
Vest4		0.83
MutPred		0.65		.;Loss of sheet (P = 0.0104);
MVP		0.86
MPC		0.44
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.89
gMVP		0.79

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs515726064; hg19: chr16-23646645;