16-23637868-G-C

Position:

• chr16-23637868-G-C

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_024675.4(PALB2):​c.193C>G​(p.Pro65Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,588 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P65L) 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: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -0.285

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 Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.06648335).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PALB2	NM_024675.4	c.193C>G	p.Pro65Ala	missense_variant	3/13	ENST00000261584.9	NP_078951.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PALB2	ENST00000261584.9	c.193C>G	p.Pro65Ala	missense_variant	3/13	1	NM_024675.4	ENSP00000261584	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251476 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135912

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460588 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726710

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial cancer of breast Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 09, 2022

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. ClinVar contains an entry for this variant (Variation ID: 482012). This variant has not been reported in the literature in individuals affected with PALB2-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.003%). This sequence change replaces proline, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 65 of the PALB2 protein (p.Pro65Ala). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 18, 2016

The p.P65A variant (also known as c.193C>G), located in coding exon 3 of the PALB2 gene, results from a C to G substitution at nucleotide position 193. The proline at codon 65 is replaced by alanine, an amino acid with highly similar properties. This variant was not reported in population based cohorts in the following databases: Database of Single Nucleotide Polymorphisms (dbSNP), NHLBI Exome Sequencing Project (ESP), and 1000 Genomes Project. In the ESP, this variant was not observed in 6497 samples (12994 alleles) with coverage at this position. To date, this alteration has been detected with an allele frequency of approximately 0.001% (greater than 130000 alleles tested) in our clinical cohort. This amino acid position is poorly 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.082
BayesDel_addAF	Benign	-0.27	T
BayesDel_noAF	Benign	-0.54
CADD	Benign	0.33
DANN	Benign	0.75
DEOGEN2	Benign	0.15	T;T
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.061	N
LIST_S2	Benign	0.38	T;T
M_CAP	Benign	0.010	T
MetaRNN	Benign	0.066	T;T
MetaSVM	Benign	-0.93	T
MutationAssessor	Uncertain	2.1	M;.
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.22	T
PROVEAN	Benign	-2.0	N;.
REVEL	Benign	0.081
Sift	Benign	0.53	T;.
Sift4G	Benign	0.75	T;.
Polyphen		0.073	B;.
Vest4		0.15
MutPred		0.12		Gain of helix (P = 0.027);.;
MVP		0.22
MPC		0.052
ClinPred		0.97	D
GERP RS		-4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.1
Varity_R		0.027
gMVP		0.017

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

LitVar

Other links and lift over

dbSNP: rs1229828972; hg19: chr16-23649189;