NM_024675.4:c.3436C>T

Variant names:

• chr16-23603584-G-A
• rs879254033
• NM_024675.4:c.3436C>T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_024675.4(PALB2):​c.3436C>T​(p.Gln1146*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. Q1146Q) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PALB2 NM_024675.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 3.50
• Publications: 3 publications found

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]

PALB2 Gene-Disease associations (from GenCC):

• hereditary breast carcinoma

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen, Ambry Genetics
• Fanconi anemia complementation group N

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
• pancreatic cancer, susceptibility to, 3

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• familial ovarian cancer

  Inheritance: AD Classification: MODERATE Submitted by: ClinGen
• Fanconi anemia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• hereditary nonpolyposis colon cancer

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 37 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 16-23603584-G-A is Pathogenic according to our data. Variant chr16-23603584-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 460994.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PALB2	NM_024675.4	c.3436C>T	p.Gln1146*	stop_gained	Exon 13 of 13	ENST00000261584.9	NP_078951.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PALB2	ENST00000261584.9	c.3436C>T	p.Gln1146*	stop_gained	Exon 13 of 13	1	NM_024675.4	ENSP00000261584.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial cancer of breast Pathogenic:2

Oct 13, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ClinVar contains an entry for this variant (Variation ID: 460994). For these reasons, this variant has been classified as Pathogenic. This variant disrupts a region of the PALB2 protein in which other variant(s) (p.Tyr1183*) have been determined to be pathogenic (PMID: 17200668, 17200671, 19609323, 20927582, 21165770, 21365267, 22241545, 26315354). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. 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 creates a premature translational stop signal (p.Gln1146*) in the PALB2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 41 amino acid(s) of the PALB2 protein. -

Sep 15, 2023

Myriad Genetics, Inc.

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered pathogenic. This variant creates a termination codon and is predicted to result in premature protein truncation. -

Hereditary cancer-predisposing syndrome Pathogenic:1

May 02, 2022

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Q1146* pathogenic mutation (also known as c.3436C>T), located in coding exon 13 of the PALB2 gene, results from a C to T substitution at nucleotide position 3436. This changes the amino acid from a glutamine to a stop codon within coding exon 13. This alteration occurs at the 3' terminus of thePALB2 gene, is not expected to trigger nonsense-mediated mRNA decay, and impacts the last 41 amino acids of the protein. However, premature stop codons are typically deleterious in nature and the impacted region is critical for protein function (Ambry internal data). Another truncating alteration downstream, p.Y1183*, has been observed in an individual with clinical features of Fanconi Anemia-N (FA-N) who carried p.Y1183* in conjunction with a PALB2 frameshift mutation and was found to have no detectable PALB2 protein in lymphoblastoid cells (Reid S et al. Nat. Genet. 2007 Feb;39:162-4). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Pathogenic	0.62
CADD	Pathogenic	37
DANN	Uncertain	1.0
Eigen	Pathogenic	0.91
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Uncertain	0.92	D
PhyloP100		3.5
Vest4		0.72
GERP RS		5.8
Mutation Taster		=1/199	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs879254033; hg19: chr16-23614905; COSMIC: COSV55164913; COSMIC: COSV55164913;