rs370243877

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM1PM2PP3_ModeratePP5_Very_Strong

The NM_018129.4(PNPO):​c.98A>T​(p.Asp33Val) variant causes a missense change. The variant allele was found at a frequency of 0.000221 in 1,567,790 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 0.00012 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00023 ( 0 hom. )

Consequence

PNPO
NM_018129.4 missense

Scores

7
9
3

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:7O:1

Conservation

PhyloP100: 4.69
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]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 ACMG points.

PM1
In a chain Pyridoxine-5'-phosphate oxidase (size 260) in uniprot entity PNPO_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) in NM_018129.4
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.877
PP5
Variant 17-47941773-A-T is Pathogenic according to our data. Variant chr17-47941773-A-T is described in ClinVar as [Pathogenic]. Clinvar id is 206458.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
PNPONM_018129.4 linkuse as main transcriptc.98A>T p.Asp33Val missense_variant 1/7 ENST00000642017.2 NP_060599.1 Q9NVS9-1V9HW45

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
PNPOENST00000642017.2 linkuse as main transcriptc.98A>T p.Asp33Val missense_variant 1/7 NM_018129.4 ENSP00000493302.2 Q9NVS9-1

Frequencies

GnomAD3 genomes
AF:
0.000118
AC:
18
AN:
152124
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000724
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.000188
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000176
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.000106
AC:
19
AN:
178538
Hom.:
0
AF XY:
0.0000940
AC XY:
9
AN XY:
95720
show subpopulations
Gnomad AFR exome
AF:
0.0000965
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:
0.000247
Gnomad NFE exome
AF:
0.000192
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000232
AC:
329
AN:
1415666
Hom.:
0
Cov.:
31
AF XY:
0.000199
AC XY:
139
AN XY:
699970
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:
0.00
Gnomad4 FIN exome
AF:
0.000120
Gnomad4 NFE exome
AF:
0.000293
Gnomad4 OTH exome
AF:
0.0000682
GnomAD4 genome
AF:
0.000118
AC:
18
AN:
152124
Hom.:
0
Cov.:
32
AF XY:
0.000135
AC XY:
10
AN XY:
74306
show subpopulations
Gnomad4 AFR
AF:
0.0000724
Gnomad4 AMR
AF:
0.0000655
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.000188
Gnomad4 NFE
AF:
0.000176
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.000198
Hom.:
0
Bravo
AF:
0.000102
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.000259
AC:
1
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000234
AC:
2
ExAC
AF:
0.0000931
AC:
11

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:7Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Pyridoxal phosphate-responsive seizures Pathogenic:4Other:1
Pathogenic, criteria provided, single submitterclinical testingVictorian Clinical Genetics Services, Murdoch Childrens Research InstituteOct 09, 2024Updated: Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with pyridoxamine 5'-phosphate oxidase deficiency (MIM#610090). (I) 0106 - This gene is associated with autosomal recessive disease. (I) 0115 - Variants in this gene are known to have variable expressivity (OMIM). (I) 0200 - Variant is predicted to result in a missense amino acid change from aspartic acid to valine. (I) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD (v2) <0.01 for a recessive condition (21 heterozygotes, 0 homozygotes). (SP) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0604 - Variant is not located in an established domain, motif, hotspot or informative constraint region. (I) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. This variant has been reported as pathogenic in ClinVar and in multiple unrelated individuals with pyridoxine phosphate oxidase deficiency (PNPO; PMIDs: 20370816, 23419474, 24645144, 27781031). (SP) 1205 - This variant has been shown to be maternally inherited (by trio analysis). (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
Pathogenic, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaAug 25, 2017The PNPO c.98A>T (p.Asp33Val) variant has been reported in four studies and is found in a total of eight patients including three in a homozygous state and five in a compound heterozygous state (Schmitt et al. 2010; Goyal et al. 2013; Mills et al. 2014; Moller et al. 2016). All individuals with the p.Asp33Val variant were identified as having pyridoxamine 5-prime-phosphate oxidase (PNPO) deficiency, and one patient was also diagnosed with West syndrome (Moller et al. 2016). One of the compound heterozygous individuals carried a complex allele, however the third variant was determined to be a polymophism (Mills et al. 2014). Control data are unavailable for this variant, which is reported at a frequency of 0.000451 in the European (non-Finnish) population of the Exome Aggregation Consortium. When expressed in HeLa cells, the p.Asp33Val variant protein exhibited a 55% reduction in PNPO activity compared to wildtype (Mills et al. 2004). Based on the evidence, the p.Asp33Val variant is classified as pathogenic for pyridoxamine 5-prime-phosphate oxidase deficiency. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -
not provided, no classification providedphenotyping onlyGenomeConnect, ClinGen-Variant classified as Pathogenic and reported on 06-02-2021 by Lab or GTR ID 500031. GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -
Pathogenic, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpMar 10, 2022Variant summary: PNPO c.98A>T (p.Asp33Val) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00011 in 178538 control chromosomes. This frequency is not significantly higher than expected for a pathogenic variant in PNPO causing Pyridoxal 5'-Phosphate-Dependent Epilepsy (0.00011 vs 0.0011), allowing no conclusion about variant significance. c.98A>T has been reported in the literature as homozygous and compound heterozygous genotypes in multiple individuals affected with and/or undergoing genetic evaluation for pyridoxine phosphate oxidase deficiency (PNPO) and/or epilepsy (example, Schmitt_2010, Goyal_2013, Sudarsanam_2014, Mills_2014, Moller_2016). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function (example, Mills_2014). The most pronounced variant effect results in 44% of normal PNPO activity. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJan 30, 2024This sequence change replaces aspartic acid, which is acidic and polar, with valine, which is neutral and non-polar, at codon 33 of the PNPO protein (p.Asp33Val). This variant is present in population databases (rs370243877, gnomAD 0.02%). This missense change has been observed in individual(s) with pyridoxal 5'-phosphate-dependent epilepsy or neonatal onset epilepsy (PMID: 20370816, 23419474, 24645144, 25256445, 27781031). ClinVar contains an entry for this variant (Variation ID: 206458). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Experimental studies have shown that this missense change affects PNPO function (PMID: 24645144). For these reasons, this variant has been classified as Pathogenic. -
not provided Pathogenic:2
Pathogenic, criteria provided, single submitterclinical testingGeneDxDec 09, 2021Published functional studies demonstrate reduced enzyme activity (Mills et al., 2014); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 26303608, 21292558, 23419474, 20370816, 17216302, 26821542, 27781031, 25762494, 24645144, 25256445, 34313030, Chi2021[functionalstudy], 32888189, 33981986, 34769443) -
Pathogenic, criteria provided, single submitterclinical testingGenetic Services Laboratory, University of ChicagoJul 11, 2017- -
Inborn genetic diseases Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingAmbry GeneticsJun 28, 2017The p.D33V pathogenic mutation (also known as c.98A>T), located in coding exon 1 of the PNPO gene, results from an A to T substitution at nucleotide position 98. The aspartic acid at codon 33 is replaced by valine, an amino acid with highly dissimilar properties. This alteration was first reported in an individual with pyridoxine phosphate oxidase deficiency (PPOD), who also had c.246delT in the PTNO gene (Hoffmann GF et al. J. Inherit. Metab. Dis., 2007 Feb;30:96-9; Schmitt B et al. Dev Med Child Neurol, 2010 Jul;52:e133-42). In addition, this alteration has also been identified in several individuals with low pyridoxal 5'-phosphate and epilepsy, in either the homozygous or compound heterozygous state (Goyal M et al. Pediatr. Neurol., 2013 Mar;48:227-31; Mills PB et al. Brain, 2014 May;137:1350-60; M&oslash;ller RS et al. Mol Syndromol, 2016 Sep;7:210-219). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.27
BayesDel_addAF
Pathogenic
0.19
D
BayesDel_noAF
Pathogenic
0.31
CADD
Pathogenic
31
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.52
D;.;.;.
Eigen
Uncertain
0.67
Eigen_PC
Uncertain
0.66
FATHMM_MKL
Pathogenic
1.0
D
LIST_S2
Uncertain
0.92
D;D;D;D
M_CAP
Pathogenic
0.37
D
MetaRNN
Pathogenic
0.88
D;D;D;D
MetaSVM
Uncertain
0.27
D
MutationAssessor
Benign
1.9
L;L;L;.
PrimateAI
Uncertain
0.74
T
PROVEAN
Pathogenic
-6.0
.;D;D;.
REVEL
Pathogenic
0.87
Sift
Uncertain
0.0010
.;D;D;.
Sift4G
Uncertain
0.0080
.;D;D;.
Polyphen
0.99
D;.;.;.
Vest4
0.75, 0.88
MVP
0.92
MPC
1.6
ClinPred
0.77
D
GERP RS
5.2
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.6
Varity_R
0.74
gMVP
0.77

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.12
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.

Other links and lift over

dbSNP: rs370243877; hg19: chr17-46019139; API