rs104894451

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1PM2PM5

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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R234P) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000031 ( 0 hom. )

Consequence

PNP
NM_000270.4 missense

Scores

3
11
4

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.74

Publications

10 publications found
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 Gene-Disease associations (from GenCC):
  • purine nucleoside phosphorylase deficiency
    Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM1
In a chain Purine nucleoside phosphorylase (size 288) in uniprot entity PNPH_HUMAN there are 12 pathogenic changes around while only 3 benign (80%) in NM_000270.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr14-20476432-G-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 13991.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PNPNM_000270.4 linkc.701G>A p.Arg234Gln missense_variant Exon 6 of 6 ENST00000361505.10 NP_000261.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PNPENST00000361505.10 linkc.701G>A p.Arg234Gln missense_variant Exon 6 of 6 1 NM_000270.4 ENSP00000354532.6

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152208
Hom.:
0
Cov.:
32
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
GnomAD2 exomes
AF:
0.0000477
AC:
12
AN:
251482
AF XY:
0.0000441
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000105
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000315
AC:
46
AN:
1461878
Hom.:
0
Cov.:
31
AF XY:
0.0000303
AC XY:
22
AN XY:
727240
show subpopulations
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:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000396
AC:
44
AN:
1112000
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.470
Heterozygous variant carriers
0
3
6
10
13
16
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
4
AN:
152208
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74358
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41454
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000588
AC:
4
AN:
68044
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.600
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000225
Hom.:
0
Bravo
AF:
0.0000227
ExAC
AF:
0.0000330
AC:
4
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
Jul 26, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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
D
BayesDel_noAF
Pathogenic
0.18
CADD
Uncertain
26
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.51
D
Eigen
Uncertain
0.61
Eigen_PC
Uncertain
0.61
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Uncertain
0.92
D
M_CAP
Uncertain
0.13
D
MetaRNN
Uncertain
0.48
T
MetaSVM
Uncertain
0.36
D
MutationAssessor
Uncertain
2.7
M
PhyloP100
7.7
PrimateAI
Uncertain
0.66
T
PROVEAN
Benign
-2.0
N
REVEL
Pathogenic
0.71
Sift
Benign
0.085
T
Sift4G
Benign
0.12
T
Vest4
0.26
ClinPred
0.49
T
GERP RS
4.6
Varity_R
0.59
gMVP
0.80
Mutation Taster
=52/48
polymorphism

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

Other links and lift over

dbSNP: rs104894451; hg19: chr14-20944591; COSMIC: COSV64091776; COSMIC: COSV64091776; API