16-23635357-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_024675.4(PALB2):c.1189A>G(p.Thr397Ala) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,688 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T397S) 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, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 5.44

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 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.817

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PALB2	NM_024675.4	c.1189A>G	p.Thr397Ala	missense_variant	4/13	ENST00000261584.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PALB2	ENST00000261584.9	c.1189A>G	p.Thr397Ala	missense_variant	4/13	1	NM_024675.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461688 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727144

Gnomad4 AFR exome AF: 0.0000299

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

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

Jan 26, 2024

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Feb 12, 2016

This variant is denoted PALB2 c.1189A>G at the cDNA level, p.Thr397Ala (T397A) at the protein level, and results in the change of a Threonine to an Alanine (ACA>GCA). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. PALB2 Thr397Ala was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, suggesting it is not a common benign variant in these populations. Since Threonine and Alanine differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. PALB2 Thr397Ala occurs at a position that is conserved across species and is located in the DNA-binding region and the chromatin-association motif (UniProt). In silico analyses predict that this variant is probably damaging to protein structure and function. Based on currently available evidence, it is unclear whether PALB2 Thr397Ala is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -

Familial cancer of breast Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 03, 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. 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. ClinVar contains an entry for this variant (Variation ID: 246419). 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 threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 397 of the PALB2 protein (p.Thr397Ala). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Uncertain	0.12	D
BayesDel_noAF	Uncertain	-0.060
Cadd	Uncertain	24
Dann	Uncertain	1.0
DEOGEN2	Benign	0.19	T;D
Eigen	Pathogenic	0.71
Eigen_PC	Pathogenic	0.67
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Benign	0.76	T;T
M_CAP	Benign	0.035	D
MetaRNN	Pathogenic	0.82	D;D
MetaSVM	Benign	-0.59	T
MutationTaster	Benign	0.83	D
PrimateAI	Benign	0.41	T
PROVEAN	Uncertain	-3.6	D;D
Sift	Pathogenic	0.0	D;D
Sift4G	Uncertain	0.016	D;D
Polyphen		1.0	.;D
Vest4		0.78
MutPred		0.60		.;Loss of glycosylation at T397 (P = 0.0294);
MVP		0.70
MPC		0.34
ClinPred		0.99	D
GERP RS		5.7
Varity_R		0.58
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: rs367578415; hg19: chr16-23646678;