17-47945985-G-A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 3P and 1B. PM1PP3BS1_Supporting

The NM_018129.4(PNPO):​c.542G>A​(p.Arg181Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00011 in 1,613,724 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R181W) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00024 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000096 ( 0 hom. )

Consequence

PNPO
NM_018129.4 missense

Scores

8
6
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 9.28

Publications

2 publications found
Variant links:
Genes affected
PNPO (HGNC:30260): (pyridoxamine 5'-phosphate oxidase) The enzyme encoded by this gene catalyzes the terminal, rate-limiting step in the synthesis of pyridoxal 5'-phosphate, also known as vitamin B6. Vitamin B6 is a required co-factor for enzymes involved in both homocysteine metabolism and synthesis of neurotransmitters such as catecholamine. Mutations in this gene result in pyridoxamine 5'-phosphate oxidase (PNPO) deficiency, a form of neonatal epileptic encephalopathy. [provided by RefSeq, Oct 2008]
PNPO Gene-Disease associations (from GenCC):
  • pyridoxal phosphate-responsive seizures
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, ClinGen, Labcorp Genetics (formerly Invitae), Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM1
In a chain Pyridoxine-5'-phosphate oxidase (size 260) in uniprot entity PNPO_HUMAN there are 18 pathogenic changes around while only 2 benign (90%) in NM_018129.4
PP3
MetaRNN computational evidence supports a deleterious effect, 0.786
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000243 (37/152214) while in subpopulation AFR AF = 0.000844 (35/41454). AF 95% confidence interval is 0.000623. There are 0 homozygotes in GnomAd4. There are 14 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PNPONM_018129.4 linkc.542G>A p.Arg181Gln missense_variant Exon 5 of 7 ENST00000642017.2 NP_060599.1 Q9NVS9-1V9HW45
PNPONM_001436305.1 linkc.418-338G>A intron_variant Intron 4 of 5 NP_001423234.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PNPOENST00000642017.2 linkc.542G>A p.Arg181Gln missense_variant Exon 5 of 7 NM_018129.4 ENSP00000493302.2 Q9NVS9-1

Frequencies

GnomAD3 genomes
AF:
0.000243
AC:
37
AN:
152214
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000844
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:
0.000478
GnomAD2 exomes
AF:
0.0000995
AC:
25
AN:
251184
AF XY:
0.0000663
show subpopulations
Gnomad AFR exome
AF:
0.00117
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000352
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000958
AC:
140
AN:
1461510
Hom.:
0
Cov.:
32
AF XY:
0.0000990
AC XY:
72
AN XY:
727050
show subpopulations
African (AFR)
AF:
0.00143
AC:
48
AN:
33472
American (AMR)
AF:
0.0000447
AC:
2
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.000302
AC:
12
AN:
39698
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86234
European-Finnish (FIN)
AF:
0.0000188
AC:
1
AN:
53180
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5678
European-Non Finnish (NFE)
AF:
0.0000594
AC:
66
AN:
1112006
Other (OTH)
AF:
0.000166
AC:
10
AN:
60382
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.488
Heterozygous variant carriers
0
8
16
24
32
40
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.000243
AC:
37
AN:
152214
Hom.:
0
Cov.:
32
AF XY:
0.000188
AC XY:
14
AN XY:
74358
show subpopulations
African (AFR)
AF:
0.000844
AC:
35
AN:
41454
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68036
Other (OTH)
AF:
0.000478
AC:
1
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.510
Heterozygous variant carriers
0
3
6
8
11
14
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.0000633
Hom.:
0
Bravo
AF:
0.000370
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000519
AC:
2
ESP6500AA
AF:
0.000681
AC:
3
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000906
AC:
11
EpiCase
AF:
0.00
EpiControl
AF:
0.000119

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Pyridoxal phosphate-responsive seizures Uncertain:2
Aug 23, 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 181 of the PNPO protein (p.Arg181Gln). This variant is present in population databases (rs377328326, gnomAD 0.1%). This variant has not been reported in the literature in individuals affected with PNPO-related conditions. ClinVar contains an entry for this variant (Variation ID: 206448). 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: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. -

Aug 06, 2021
New York Genome Center
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Uncertain:1
Jan 19, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.542G>A (p.R181Q) alteration is located in exon 5 (coding exon 5) of the PNPO gene. This alteration results from a G to A substitution at nucleotide position 542, causing the arginine (R) at amino acid position 181 to be replaced by a glutamine (Q). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1
May 05, 2022
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.71
BayesDel_addAF
Uncertain
0.080
D
BayesDel_noAF
Pathogenic
0.31
CADD
Pathogenic
33
DANN
Uncertain
0.99
DEOGEN2
Benign
0.22
T;D;.;.
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
1.0
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.96
D;D;D;D
M_CAP
Uncertain
0.25
D
MetaRNN
Pathogenic
0.79
D;D;D;D
MetaSVM
Pathogenic
0.80
D
MutationAssessor
Pathogenic
4.1
.;H;.;.
PhyloP100
9.3
PrimateAI
Uncertain
0.49
T
Sift4G
Uncertain
0.0040
D;.;.;.
Polyphen
1.0
.;D;.;.
MVP
0.98
ClinPred
0.70
D
GERP RS
5.8
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.0
Varity_R
0.81
gMVP
0.72
Mutation Taster
=29/71
disease causing

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

Other links and lift over

dbSNP: rs377328326; hg19: chr17-46023351; API