16-23641109-C-G

Position:

• chr16-23641109-C-G

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP3_Strong PP5

The NM_001407304.1(PALB2):​c.-1695G>C variant causes a 5 prime UTR premature start codon gain 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 Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: PALB2 NM_001407304.1 5_prime_UTR_premature_start_codon_gain
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3 U:1
• Conservation: PhyloP100: 1.60

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 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: BayesDel_addAF computational evidence supports a deleterious effect, 0.604
• PP5: Variant 16-23641109-C-G is Pathogenic according to our data. Variant chr16-23641109-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 126750.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PALB2	NM_024675.4	c.48+1G>C		splice_donor_variant, intron_variant		ENST00000261584.9	NP_078951.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PALB2	ENST00000261584.9	c.48+1G>C		splice_donor_variant, intron_variant		1	NM_024675.4	ENSP00000261584.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Familial cancer of breast Pathogenic:2

Likely pathogenic, no assertion criteria provided	curation	Leiden Open Variation Database	May 13, 2019	Curators: Marc Tischkowitz, Arleen D. Auerbach. Submitters to LOVD: Alfons Meindl, Marc Tischkowitz. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Mar 01, 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. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 16, 2015

The c.48+1G>C intronic variant results from a G to C substitution one nucleotide after coding exon 1 of the PALB2 gene. This variant was first reported in an individual with breast cancer and family history of breast cancer (Hellebrand H, et al. Hum. Mutat. 2011 Jun; 32(6):E2176-88). Using the BDGP and ESEfinder splice site prediction tools, this alteration is predicted to abolish the native donor splice site; however, direct evidence is unavailable. 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. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Dec 22, 2015

This variant is denoted PALB2 c.48+1G>C or IVS1+1G>C and consists of a G>C nucleotide substitution at the +1 position of intron 1 of the PALB2 gene. This variant destroys a canonical splice donor site and is predicted to cause skipping of exon 2, resulting in an in-frame deletion of 20 amino acids that are not part of a critical functional domain. This variant has been reported in an individual with a personal and family history of breast cancer (Hellebrand 2011). Based on the current evidence, we consider PALB2 c.48+1G>C to be a variant of uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Pathogenic	0.20
CADD	Pathogenic	34
DANN	Uncertain	0.98
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Benign	0.50	D
GERP RS		4.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.95
SpliceAI score (max)		0.94		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.45		Position offset: -8
DS_DL_spliceai		0.94		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: rs515726118; hg19: chr16-23652430;