16-23635357-T-G

Variant summary

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

The NM_024675.4(PALB2):c.1189A>C(p.Thr397Pro) variant causes a missense change. The variant allele was found at a frequency of 0.00000248 in 1,613,936 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: 𝑓 0.000020 (0 hom., 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: 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, 0.784

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PALB2	NM_024675.4	c.1189A>C	p.Thr397Pro	missense_variant	4/13	ENST00000261584.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PALB2	ENST00000261584.9	c.1189A>C	p.Thr397Pro	missense_variant	4/13	1	NM_024675.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152248 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.000282

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461688 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152248 Hom.: 0 Cov.: 32 AF XY: 0.0000403 AC XY: 3 AN XY: 74388

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.000282

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial cancer of breast;C1835817:Fanconi anemia complementation group N;C3150547:Pancreatic cancer, susceptibility to, 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Sep 14, 2021

- -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 20, 2021

The p.T397P variant (also known as c.1189A>C), located in coding exon 4 of the PALB2 gene, results from an A to C substitution at nucleotide position 1189. The threonine at codon 397 is replaced by proline, an amino acid with highly similar properties. This amino acid position is highly 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

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Nov 19, 2022

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: 818541). 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 proline, which is neutral and non-polar, at codon 397 of the PALB2 protein (p.Thr397Pro). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.070
Cadd	Uncertain	24
Dann	Uncertain	1.0
DEOGEN2	Benign	0.20	T;D
Eigen	Pathogenic	0.71
Eigen_PC	Pathogenic	0.67
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Benign	0.72	T;T
M_CAP	Benign	0.052	D
MetaRNN	Pathogenic	0.78	D;D
MetaSVM	Benign	-0.71	T
MutationTaster	Benign	0.96	D
PrimateAI	Benign	0.42	T
PROVEAN	Pathogenic	-4.4	D;D
Sift	Pathogenic	0.0	D;D
Sift4G	Uncertain	0.0080	D;D
Polyphen		1.0	.;D
Vest4		0.70
MutPred		0.60		.;Gain of catalytic residue at T397 (P = 0.0357);
MVP		0.76
MPC		0.38
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.85
gMVP		0.65

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;