rs199866228

Variant names:

Variant summary

Our verdict is Benign. Variant got -14 ACMG points: 2P and 16B. PM2BP4_StrongBP6_Very_StrongBS1

The NM_000270.4(PNP):c.653-4T>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000161 in 1,610,558 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.00093 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000081 ( 0 hom. )

Consequence

PNP
NM_000270.4 splice_region, intron

Scores

Splicing: ADA: 0.00005511

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:4

Conservation

PhyloP100: -0.393

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:

ENSG00000258908 (HGNC:):

ENSG00000258908 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -14 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.69).

BP6

Variant 14-20476380-T-C is Benign according to our data. Variant chr14-20476380-T-C is described in ClinVar as [Likely_benign]. Clinvar id is 391026.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.000926 (141/152338) while in subpopulation AFR AF= 0.00289 (120/41578). AF 95% confidence interval is 0.00247. There are 0 homozygotes in gnomad4. There are 64 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PNP	NM_000270.4 link	c.653-4T>C		splice_region_variant, intron_variant	Intron 5 of 5	ENST00000361505.10	NP_000261.2	P00491V9HWH6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PNP	ENST00000361505.10 link	c.653-4T>C		splice_region_variant, intron_variant	Intron 5 of 5	1	NM_000270.4	ENSP00000354532.6		P00491

Frequencies

GnomAD3 genomes

AF:

0.000926

AC:

141

AN:

152220

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00289

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00124

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000219

AC:

AN:

251438

Hom.:

AF XY:

0.000147

AC XY:

AN XY:

135898

show subpopulations

Gnomad AFR exome

AF:

0.00215

Gnomad AMR exome

AF:

0.000318

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:

0.0000616

Gnomad OTH exome

AF:

0.000326

GnomAD4 exome

AF:

0.0000809

AC:

118

AN:

1458220

Hom.:

Cov.:

AF XY:

0.0000841

AC XY:

AN XY:

725696

show subpopulations

Gnomad4 AFR exome

AF:

0.00180

Gnomad4 AMR exome

AF:

0.000492

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:

0.0000162

Gnomad4 OTH exome

AF:

0.000249

GnomAD4 genome

AF:

0.000926

AC:

141

AN:

152338

Hom.:

Cov.:

AF XY:

0.000859

AC XY:

AN XY:

74480

show subpopulations

Gnomad4 AFR

AF:

0.00289

Gnomad4 AMR

AF:

0.00124

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000343

Hom.:

Bravo

AF:

0.000842

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.0000545

EpiControl

AF:

0.000178

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:2

May 01, 2023

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

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: PNP c.653-4T>C alters a non-conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. 4/4 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.00093 in 150992 control chromosomes, predominantly at a frequency of 0.0029 within the African or African-American subpopulation in the gnomAD database (v3.1, genomes dataset). The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 8-fold of the estimated maximal expected allele frequency for a pathogenic variant in PNP causing Severe Combined Immunodeficiency phenotype (0.00035), strongly suggesting that the variant is a benign polymorphism found primarily in populations of African or African-American origin. To our knowledge, no occurrence of c.653-4T>C in individuals affected with Severe Combined Immunodeficiency and no experimental evidence demonstrating its impact on protein function have been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014, and classified the variant as benign (n=1)/likely benign(n=1). Based on the evidence outlined above, the variant was classified as benign. -

Nov 16, 2016

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Purine-nucleoside phosphorylase deficiency

Benign:1

Feb 02, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

PNP-related disorder

Benign:1

Jun 10, 2024

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.69

CADD

Benign

5.6

DANN

Benign

0.75

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.000055

dbscSNV1_RF

Benign

0.0

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

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