rs1060499814

Positions:

• chr16-23638069-C-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1_Moderate PM2 PP3_Strong PP5_Very_Strong

The NM_024675.4(PALB2):​c.108+1G>A variant causes a splice donor change. The variant allele was found at a frequency of 0.00000657 in 152,138 control chromosomes in the GnomAD database, with no homozygous occurrence. 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: 𝑓 0.0000066 (0 hom., 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:10
• Conservation: PhyloP100: 4.78

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 Pathogenic. Variant got 16 ACMG points.

• PVS1: Splicing variant, NOT destroyed by nmd, known LOF gene, truncates exone, which is 0.01656838 fraction of the gene. No cryptic splice site detected. Exon removal is inframe 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 16-23638069-C-T is Pathogenic according to our data. Variant chr16-23638069-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 402289.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.108+1G>A		splice_donor_variant		ENST00000261584.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PALB2	ENST00000261584.9	c.108+1G>A		splice_donor_variant		1	NM_024675.4	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152138 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 30

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152138 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74328

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000655

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:10

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial cancer of breast Pathogenic:4

Likely pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Mar 30, 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. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Jan 24, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 06, 2024	This sequence change affects a donor splice site in intron 2 of the PALB2 gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in a shortened 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: 35264596). ClinVar contains an entry for this variant (Variation ID: 402289). Studies have shown that disruption of this splice site results in skipping of exon 2, but is expected to preserve the integrity of the reading-frame (PMID: 34846068; Invitae). This variant disrupts a region of the PALB2 protein in which other variant(s) (p.Leu35Pro) have been determined to be pathogenic (PMID: 28319063, 30337689, 31586400, 31636395, 31757951, 33169439, 33964450). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Mendelics	May 28, 2019	- -

not provided Pathogenic:3

Likely pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Mar 01, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Oct 07, 2022	This variant disrupts a canonical splice-donor site and interferes with normal PALB2 mRNA splicing. The variant has not been reported in individuals with PALB2-related diseases in the published literature. It also has not been reported in large, multi-ethnic general populations (http://gnomad.broadinstitute.org). Based on the available information, this variant is classified as pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Dec 15, 2016	This variant is denoted PALB2 c.108+1G>A or IVS2+1G>A and consists of a G>A nucleotide substitution at the +1 position of intron 2 of the PALB2 gene. This 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.108+1G>A to be a likely pathogenic variant. -

Hereditary cancer-predisposing syndrome Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	May 23, 2023	The c.108+1G>A intronic variant results from a G to A substitution one nucleotide after coding exon 2 of the PALB2 gene. Alterations that disrupt the canonical splice site are expected to result in aberrant splicing. 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. The resulting transcript is predicted to be in-frame and is not expected to trigger nonsense-mediated mRNA decay. RNA studies have demonstrated that this variant was associated with in-frame exon 2 skipping (Valenzuela-Palomo A et al. J Pathol, 2022 Mar;256:321-334, Ambry internal data). The exact functional effect of the altered amino acid sequence is unknown; however, the impacted region is critical for protein function (Ambry internal data). This variant has been seen in multiple breast cancer patients (Dorling et al. N Engl J Med 2021 02;384:428-439; Guindalini RSC et al. Sci Rep, 2022 Mar;12:4190). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Nov 01, 2022	This variant causes a G to A nucleotide substitution at the +1 position of intron 2 of the PALB2 gene. Splice site prediction tools predict that this variant may have a significant impact on RNA splicing. RNA studies have shown that this variant causes in-frame skipping of exon 2, resulting in loss of the BRCA1 binding domain (PMID: 34846068). This variant has been reported in 2 individuals affected with breast cancer (DOI: 10.21149/12704, Color internal data). 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. -

Pancreatic cancer, susceptibility to, 3;C3469522:Breast cancer, susceptibility to Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Human Genome Sequencing Center Clinical Lab, Baylor College of Medicine

Sep 27, 2018

The c.108+1G>A variant in the PALB2 gene is predicted to disrupt a canonical splice donor site. This variant has not been observed in the gnomAD database. Therefore, the c.108+1G>A variant in the PALB2 gene is classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Pathogenic	0.38
CADD	Pathogenic	32
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Uncertain	0.94	D
MutationTaster	Benign	1.0	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.8

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: rs1060499814; hg19: chr16-23649390;