chr16-23614073-T-G

Position:

• chr16-23614073-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_024675.4(PALB2):​c.3132A>C​(p.Gln1044His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,459,946 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another nucleotide change resulting in same amino acid change has been previously reported as Uncertain significancein ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q1044K) has been classified 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:3
• Conservation: PhyloP100: 0.0950

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]

(HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PALB2	NM_024675.4	c.3132A>C	p.Gln1044His	missense_variant	11/13	ENST00000261584.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PALB2	ENST00000261584.9	c.3132A>C	p.Gln1044His	missense_variant	11/13	1	NM_024675.4	P1
	ENST00000561764.1	n.186-3527T>G		intron_variant, non_coding_transcript_variant		2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1459946 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726420

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: 0.00000450

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 provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Aug 05, 2016

This variant is denoted PALB2 c.3132A>C at the cDNA level, p.Gln1044His (Q1044H) at the protein level, and results in the change of a Glutamine to a Histidine (CAA>CAC). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. PALB2 Gln1044His was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. Since Glutamine and Histidine differ in some properties, this is considered a semi-conservative amino acid substitution and may affect protein integrity. PALB2 Gln1044His occurs at a position that is highly conserved across species and is located in within a region that interacts with RAD51 and BRCA2 as well as the WD4 repeat region. In silico analyses predict that this variant is probably damaging to protein structure and function. Based on currently available information, it is unclear whether PALB2 Gln1044His is pathogenic or benign. We consider it to be a variant of uncertain significance. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 15, 2021

The p.Q1044H variant (also known as c.3132A>C), located in coding exon 11 of the PALB2 gene, results from an A to C substitution at nucleotide position 3132. The glutamine at codon 1044 is replaced by histidine, an amino acid with highly similar properties. This alteration was found to be functionally normal in a homology-directed DNA repair (HDR) assay (Wiltshire T et al. Genet Med, 2020 03;22:622-632). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. 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

Labcorp Genetics (formerly Invitae), Labcorp

Dec 30, 2023

This sequence change replaces glutamine, which is neutral and polar, with histidine, which is basic and polar, at codon 1044 of the PALB2 protein (p.Gln1044His). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with PALB2-related conditions. ClinVar contains an entry for this variant (Variation ID: 128138). 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 not expected to disrupt PALB2 protein function with a negative predictive value of 80%. Experimental studies have shown that this missense change does not substantially affect PALB2 function (PMID: 31636395). 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	Uncertain	0.36
BayesDel_addAF	Benign	-0.015	T
BayesDel_noAF	Benign	-0.26
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Benign	0.12	T;T
Eigen	Uncertain	0.23
Eigen_PC	Benign	0.10
FATHMM_MKL	Benign	0.64	D
LIST_S2	Uncertain	0.88	D;D
M_CAP	Benign	0.030	D
MetaRNN	Uncertain	0.62	D;D
MetaSVM	Benign	-0.82	T
MutationAssessor	Uncertain	2.1	.;M
MutationTaster	Benign	0.98	D
PrimateAI	Benign	0.48	T
PROVEAN	Uncertain	-4.1	D;D
REVEL	Benign	0.23
Sift	Uncertain	0.0040	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	.;D
Vest4		0.76
MutPred		0.35		.;Gain of catalytic residue at L1046 (P = 0.0706);
MVP		0.48
MPC		0.33
ClinPred		1.0	D
GERP RS		-2.2
Varity_R		0.65
gMVP		0.44

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs587780216; hg19: chr16-23625394;