16-23624008-C-T

Variant summary

Our verdict is Pathogenic. Variant got 22 ACMG points: 22P and 0B. PVS1 PM2 PP3_Strong PP5_Very_Strong

The NM_024675.4(PALB2):c.2834+1G>A variant causes a splice donor change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: PALB2 NM_024675.4 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:9
• Conservation: PhyloP100: 4.71

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 Pathogenic. Variant got 22 ACMG points.

• PVS1: Splicing variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 16-23624008-C-T is Pathogenic according to our data. Variant chr16-23624008-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 182771.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PALB2	NM_024675.4	c.2834+1G>A		splice_donor_variant		ENST00000261584.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PALB2	ENST00000261584.9	c.2834+1G>A		splice_donor_variant		1	NM_024675.4	P1
	ENST00000561764.1	n.528C>T		non_coding_transcript_exon_variant	4/4	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:9

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial cancer of breast Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Institute of Human Genetics, University of Leipzig Medical Center	Dec 06, 2021	_x000D_ Criteria applied: PVS1_STR, PM5_STR, PS4_MOD, PM2_SUP -
Likely pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Sep 13, 2023	This variant is considered likely pathogenic. This variant occurs within a consensus splice junction and is predicted to result in abnormal mRNA splicing of either an out-of-frame exon or an in-frame exon necessary for protein stability and/or normal function. -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Dec 18, 2023	This sequence change affects a donor splice site in intron 8 of the PALB2 gene. RNA analysis indicates that disruption of this splice site induces altered splicing and may result in an absent or disrupted protein product. This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with breast cancer (PMID: 26681312; Invitae). It has also been observed to segregate with disease in related individuals. This variant is also known as IVS8+1G>A. ClinVar contains an entry for this variant (Variation ID: 182771). Studies have shown that disruption of this splice site results in skipping of exon 8 and/or intronic inclusion and introduces a premature termination codon (Invitae). The resulting mRNA is expected to undergo nonsense-mediated decay. For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen	Oct 23, 2020	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Oct 13, 2017	This likely pathogenic variant is denoted PALB2 c.2834+1G>A or IVS8+1G>A and consists of a G>A nucleotide substitution at the +1 position of intron 8 of the PALB2 gene. The variant destroys a canonical splice donor site and is predicted to cause abnormal gene splicing, leading to either an abnormal message that is subject to nonsense-mediated mRNA decay or to an abnormal protein product. This variant has not, to our knowledge, been published in the literature. Based on the currently available information, we consider PALB2 c.2834+1G>A to be a likely pathogenic variant. -

Hereditary cancer-predisposing syndrome Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Jan 26, 2024	The c.2834+1G>A intronic variant results from a G to A substitution one nucleotide after coding exon 8 of the PALB2 gene. In one study, this variant was reported in 2/60,466 breast cancer cases and in 0/53,461 controls (Dorling et al. N Engl J Med. 2021 02;384:428-439). This alteration was identified in 1/10030 consecutive patients referred for evaluation by an NGS hereditary cancer panel. (Susswein LR et al. Genet Med, 2016 08;18:823-32) and in a cohort of 4439 women with ovarian cancer undergoing multigene panel testing at one laboratory (Carter NJ et al. Gynecol Oncol, 2018 12;151:481-488). In a large Chinese study, this alteration was not identified in 21216 unselected patients with breast cancer and was detected in 1/5890 healthy female controls (Zhou J et al. Cancer, 2020 Jul;126:3202-3208). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site; however, direct evidence is insufficient at this time (Ambry internal data). Alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. As such, this alteration is classified as likely pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Feb 04, 2020	This variant causes a G>A nucleotide substitution at the +1 position of intron 8 of the PALB2 gene. Splice site prediction tools suggest that this variant may have a significant impact on RNA splicing. Although this prediction has not been confirmed in published RNA studies, this variant is expected to result in an absent or disrupted protein product. This variant has been reported in an individual affected with breast cancer (PMID: 26681312). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of PALB2 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Likely Pathogenic. -

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

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Jan 20, 2022

- -

Malignant tumor of breast Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Department of Pediatrics, University Hospital Center Zagreb

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- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Pathogenic	0.38
Cadd	Pathogenic	29
Dann	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.98
FATHMM_MKL	Uncertain	0.92	D
MutationTaster	Benign	1.0	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.98		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs587776419; hg19: chr16-23635329;