14-20476432-G-A

Position:

chr14-20476432-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_000270.4(PNP):c.701G>A(p.Arg234Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000031 in 1,614,086 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

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

Exomes 𝑓: 0.000031 ( 0 hom. )

Consequence

PNP
NM_000270.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.74

Variant links:

Genes affected

PNP (HGNC:7892): (purine nucleoside phosphorylase) This gene encodes an enzyme which reversibly catalyzes the phosphorolysis of purine nucleosides. The enzyme is trimeric, containing three identical subunits. Mutations which result in nucleoside phosphorylase deficiency result in defective T-cell (cell-mediated) immunity but can also affect B-cell immunity and antibody responses. Neurologic disorders may also be apparent in patients with immune defects. A known polymorphism at aa position 51 that does not affect enzyme activity has been described. A pseudogene has been identified on chromosome 2. [provided by RefSeq, Jul 2008]

PNP links:

(HGNC:):

links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PNP	NM_000270.4 linkuse as main transcript	c.701G>A	p.Arg234Gln	missense_variant	6/6	ENST00000361505.10	NP_000261.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PNP	ENST00000361505.10 linkuse as main transcript	c.701G>A	p.Arg234Gln	missense_variant	6/6	1	NM_000270.4	ENSP00000354532	P1
	ENST00000554678.1 linkuse as main transcript	n.186+472C>T		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152208

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000477

AC:

AN:

251482

Hom.:

AF XY:

0.0000441

AC XY:

AN XY:

135916

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

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:

0.000105

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000315

AC:

AN:

1461878

Hom.:

Cov.:

AF XY:

0.0000303

AC XY:

AN XY:

727240

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000396

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152208

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74358

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000588

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000225

Hom.:

Bravo

AF:

0.0000227

ExAC

AF:

0.0000330

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Purine-nucleoside phosphorylase deficiency

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 26, 2022

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 234 of the PNP protein (p.Arg234Gln). This variant is present in population databases (rs104894451, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with PNP-related conditions. ClinVar contains an entry for this variant (Variation ID: 1000043). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant disrupts the p.Arg234 amino acid residue in PNP. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 1384322, 9067751, 22132981). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.12

BayesDel_addAF

Uncertain

0.15

BayesDel_noAF

Pathogenic

0.18

CADD

Uncertain

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.51

Eigen

Uncertain

0.61

Eigen_PC

Uncertain

0.61

FATHMM_MKL

Uncertain

0.95

LIST_S2

Uncertain

0.92

M_CAP

Uncertain

0.13

MetaRNN

Uncertain

0.48

MetaSVM

Uncertain

0.36

MutationAssessor

Uncertain

2.7

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.66

PROVEAN

Benign

-2.0

REVEL

Pathogenic

0.71

Sift

Benign

0.085

Sift4G

Benign

0.12

Polyphen

0.99

Vest4

0.26

MutPred

0.61

Loss of sheet (P = 0.0817);

MVP

0.95

MPC

0.69

ClinPred

0.49

GERP RS

4.6

Varity_R

0.59

gMVP

0.80

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over