NM_024675.4:c.505C>A

Variant names:

• chr16-23636041-G-T
• rs180177086
• NM_024675.4:c.505C>A

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 4P and 3B. PM1 PM2 BP4_Moderate BP6

The NM_024675.4(PALB2):​c.505C>A​(p.Leu169Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,880 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L169V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: PALB2 NM_024675.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:1
• Conservation: PhyloP100: 0.999
• Publications: 6 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: Uncertain_significance. The variant received 1 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 38 uncertain in NM_024675.4
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.13583419).
• BP6: Variant 16-23636041-G-T is Benign according to our data. Variant chr16-23636041-G-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 126755.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_024675.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PALB2	NM_024675.4	MANE Select	c.505C>A	p.Leu169Ile	missense	Exon 4 of 13	NP_078951.2
	PALB2	NM_001407296.1		c.445C>A	p.Leu149Ile	missense	Exon 3 of 12	NP_001394225.1
	PALB2	NM_001407297.1		c.505C>A	p.Leu169Ile	missense	Exon 4 of 12	NP_001394226.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PALB2	ENST00000261584.9	TSL:1 MANE Select	c.505C>A	p.Leu169Ile	missense	Exon 4 of 13	ENSP00000261584.4
	PALB2	ENST00000568219.5	TSL:1	c.-381C>A		5_prime_UTR	Exon 4 of 13	ENSP00000454703.2
	PALB2	ENST00000561514.3	TSL:5	c.511C>A	p.Leu171Ile	missense	Exon 4 of 13	ENSP00000460666.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461880 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727240

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112008

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Familial cancer of breast Uncertain:2

May 13, 2019

Leiden Open Variation Database

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: curation

Curators: Marc Tischkowitz, Arleen D. Auerbach. Submitter to LOVD: Marc Tischkowitz.

Jul 17, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Experimental studies have shown that this missense change does not substantially affect PALB2 function (PMID: 31636395, 33139182). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 126755). 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 replaces leucine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 169 of the PALB2 protein (p.Leu169Ile).

Hereditary cancer-predisposing syndrome Benign:1

Feb 19, 2024

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.20	T
BayesDel_noAF	Benign	-0.52
CADD	Benign	17
DANN	Uncertain	0.99
DEOGEN2	Benign	0.29	T
Eigen	Benign	-0.10
Eigen_PC	Benign	-0.27
FATHMM_MKL	Benign	0.11	N
LIST_S2	Benign	0.74	T
M_CAP	Benign	0.021	T
MetaRNN	Benign	0.14	T
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.7	M
PhyloP100		1.0
PrimateAI	Benign	0.27	T
PROVEAN	Benign	-1.1	N
REVEL	Benign	0.065
Sift	Benign	0.050	D
Sift4G	Benign	0.14	T
Polyphen		0.97	D
Vest4		0.16
MutPred		0.17		Gain of MoRF binding (P = 0.078)
MVP		0.31
MPC		0.34
ClinPred		0.51	D
GERP RS		3.8
Varity_R		0.085
gMVP		0.073

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: rs180177086; hg19: chr16-23647362;