rs104894450

Positions:

• chr14-20474870-A-G

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PP3_Strong PP5_Moderate

The NM_000270.4(PNP):​c.383A>G​(p.Asp128Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000558 in 1,614,036 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000061 (0 hom.)
• Consequence: PNP NM_000270.4 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 9.16

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 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.979
• PP5: Variant 14-20474870-A-G is Pathogenic according to our data. Variant chr14-20474870-A-G is described in ClinVar as [Pathogenic]. Clinvar id is 13990.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PNP	NM_000270.4	c.383A>G	p.Asp128Gly	missense_variant	4/6	ENST00000361505.10	NP_000261.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PNP	ENST00000361505.10	c.383A>G	p.Asp128Gly	missense_variant	4/6	1	NM_000270.4	ENSP00000354532.6

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152156 Hom.: 0 Cov.: 32

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.0000609 AC: 89 AN: 1461880 Hom.: 0 Cov.: 32 AF XY: 0.0000633 AC XY: 46 AN XY: 727240

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000800

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152156 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74320

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: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

EpiCase AF: 0.000109

EpiControl AF: 0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Purine-nucleoside phosphorylase deficiency Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Apr 07, 2023	Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt PNP protein function. For these reasons, this variant has been classified as Pathogenic. Experimental studies have shown that this missense change affects PNP function (PMID: 1384322). ClinVar contains an entry for this variant (Variation ID: 13990). This missense change has been observed in individual(s) with purine nucleoside phosphorylase (PNP) deficiency (PMID: 1384322, 22132981, 24767876). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces aspartic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 128 of the PNP protein (p.Asp128Gly). -
Pathogenic, no assertion criteria provided	literature only	OMIM	Oct 01, 1992	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.75
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.50
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.84	D;.;D
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.92
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Pathogenic	0.38	D
MetaRNN	Pathogenic	0.98	D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.2	M;.;.
PrimateAI	Uncertain	0.61	T
PROVEAN	Pathogenic	-6.5	D;D;D
REVEL	Pathogenic	0.96
Sift	Uncertain	0.0030	D;D;D
Sift4G	Uncertain	0.0040	D;D;D
Polyphen		1.0	D;.;.
Vest4		0.95
MutPred		0.86		Loss of ubiquitination at K123 (P = 0.0583);.;.;
MVP		1.0
MPC		1.0
ClinPred		1.0	D
GERP RS		6.0
Varity_R		0.95
gMVP		0.96

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: rs104894450; hg19: chr14-20943029;