16-23641138-T-C

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM1BP4_Moderate

The NM_024675.4(PALB2):c.20A>G(p.Lys7Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,613,306 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 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. K7M) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

PALB2
NM_024675.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:9B:1

Conservation

PhyloP100: 0.377

Publications

1 publications found

Variant links:

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

PALB2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 11 benign, 34 uncertain in NM_024675.4

BP4

Computational evidence support a benign effect (MetaRNN=0.14199886).

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

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
PALB2	NM_024675.4	MANE Select	c.20A>G	p.Lys7Arg	missense	Exon 1 of 13	NP_078951.2
PALB2	NM_001407296.1		c.20A>G	p.Lys7Arg	missense	Exon 1 of 12	NP_001394225.1
PALB2	NM_001407297.1		c.20A>G	p.Lys7Arg	missense	Exon 1 of 12	NP_001394226.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
PALB2	ENST00000261584.9	TSL:1 MANE Select	c.20A>G	p.Lys7Arg	missense	Exon 1 of 13	ENSP00000261584.4
PALB2	ENST00000568219.5	TSL:1	c.-849A>G		5_prime_UTR	Exon 1 of 13	ENSP00000454703.2
PALB2	ENST00000713774.1		c.20A>G	p.Lys7Arg	missense	Exon 1 of 11	ENSP00000519076.1

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152150

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000966

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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

AF:

0.00000137

AC:

AN:

1461156

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

726848

show subpopulations

African (AFR)

AF:

0.0000598

AC:

AN:

33458

American (AMR)

AF:

0.00

AC:

AN:

44682

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26090

East Asian (EAS)

AF:

0.00

AC:

AN:

39696

South Asian (SAS)

AF:

0.00

AC:

AN:

86144

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53372

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5546

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111856

Other (OTH)

AF:

0.00

AC:

AN:

60312

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152150

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74344

show subpopulations

African (AFR)

AF:

0.0000966

AC:

AN:

41428

American (AMR)

AF:

0.00

AC:

AN:

15276

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5186

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68026

Other (OTH)

AF:

0.00

AC:

AN:

2088

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.538

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000264

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:9Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome

Uncertain:3

Jan 31, 2022

Sema4, Sema4

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:curation

Aug 26, 2020

Color Diagnostics, LLC DBA Color Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This missense variant replaces lysine with arginine at codon 7 of the PALB2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with colorectal cancer (PMID: 27978560). This variant has been identified in 1/31370 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance.

Apr 26, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.K7R variant (also known as c.20A>G), located in coding exon 1 of the PALB2 gene, results from an A to G substitution at nucleotide position 20. The lysine at codon 7 is replaced by arginine, an amino acid with highly similar properties. This alteration has been previously identified in an individual from a North American cohort of individuals with early onset colon cancer (Pearlman R et al. JAMA Oncol, 2017 Apr;3:464-471). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.

Familial cancer of breast

Uncertain:2Benign:1

Jan 31, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces lysine, which is basic and polar, with arginine, which is basic and polar, at codon 7 of the PALB2 protein (p.Lys7Arg). This variant is present in population databases (no rsID available, gnomAD 0.01%). This missense change has been observed in individual(s) with colorectal cancer (PMID: 27978560). ClinVar contains an entry for this variant (Variation ID: 421024). An algorithm developed to predict the effect of missense changes on protein structure and function outputs the following: PolyPhen-2: "Probably Damaging". The arginine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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.

Sep 28, 2023

Myriad Genetics, Inc.

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant is considered likely benign. This variant is strongly associated with less severe personal and family histories of cancer, typical for individuals without pathogenic variants in this gene [PMID: 25085752].

Aug 15, 2023

Baylor Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

not provided

Uncertain:2

May 05, 2023

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The frequency of this variant in the general population, 0.000032 (1/31370 chromosomes, http://gnomad.broadinstitute.org), is uninformative in assessment of its pathogenicity. In the published literature, the variant has been reported in an individual with colorectal cancer (PMID: 27978560 (2016)). Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant.

Jun 24, 2020

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed at a significant frequency in large population cohorts (Lek 2016); In silico analysis supports that this missense variant does not alter protein structure/function; Observed in individuals with colorectal cancer (Pearlman 2017); This variant is associated with the following publications: (PMID: 27978560)

not specified

Uncertain:1

May 06, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: PALB2 c.20A>G (p.Lys7Arg) results in a conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. The variant was absent in 247972 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.20A>G has been reported in the literature in at least one individual affected with colon cancer, however without strong evidence for causality (e.g., Pearlman_2017). This report therefore does not provide unequivocal conclusions about association of the variant with Prostate Cancer. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 27978560). ClinVar contains an entry for this variant (Variation ID: 421024). Based on the evidence outlined above, the variant was classified as uncertain significance.

PALB2-related disorder

Uncertain:1

Sep 18, 2023

PreventionGenetics, part of Exact Sciences

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The PALB2 c.20A>G variant is predicted to result in the amino acid substitution p.Lys7Arg. This variant has been reported in an individual with colon cancer along with a second PALB2 variant (Patient 423046, eTable2, Pearlman et al. 2017. PubMed ID: 27978560). This variant is reported in 0.011% of alleles in individuals of African descent in gnomAD (http://gnomad.broadinstitute.org/variant/16-23652459-T-C), and is reported in ClinVar as uncertain (https://www.ncbi.nlm.nih.gov/clinvar/variation/421024/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence.

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.10

BayesDel_addAF

Benign

-0.14

BayesDel_noAF

Benign

-0.44

CADD

Uncertain

(source)

DANN

Benign

0.94

DEOGEN2

Benign

0.22

Eigen

Benign

-0.10

Eigen_PC

Benign

-0.0056

FATHMM_MKL

Benign

0.12

LIST_S2

Benign

0.67

M_CAP

Benign

0.0095

MetaRNN

Benign

0.14

MetaSVM

Benign

-1.0

MutationAssessor

Uncertain

2.1

PhyloP100

0.38

PrimateAI

Uncertain

0.55

PROVEAN

Benign

-1.6

REVEL

Benign

0.035

Sift

Pathogenic

0.0

Sift4G

Benign

0.25

Polyphen

0.21

Vest4

0.18

MutPred

0.20

Loss of ubiquitination at K7 (P = 0.002)

MVP

0.45

MPC

0.32

ClinPred

0.94

GERP RS

3.1

PromoterAI

-0.010

Neutral

(source)

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.6

Varity_R

0.18

gMVP

0.017

Mutation Taster

=94/6

polymorphism

(source)

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over