NM_032634.4:c.737C>T

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP3

The NM_032634.4(PIGO):​c.737C>T​(p.Pro246Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000062 in 1,614,016 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. P246R) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

PIGO
NM_032634.4 missense

Scores

8
8
3

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 9.91

Publications

1 publications found
Variant links:
Genes affected
PIGO (HGNC:23215): (phosphatidylinositol glycan anchor biosynthesis class O) This gene encodes a protein that is involved in glycosylphosphatidylinositol (GPI)-anchor biosynthesis. The GPI-anchor is a glycolipid which contains three mannose molecules in its core backbone. The GPI-anchor is found on many blood cells and serves to anchor proteins to the cell surface. This protein is involved in the transfer of ethanolaminephosphate (EtNP) to the third mannose in GPI. At least three alternatively spliced transcripts encoding two distinct isoforms have been found for this gene. [provided by RefSeq, Jan 2011]
PIGO Gene-Disease associations (from GenCC):
  • complex neurodevelopmental disorder
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • hyperphosphatasia with intellectual disability syndrome 2
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Illumina, Labcorp Genetics (formerly Invitae), PanelApp Australia
  • hyperphosphatasia-intellectual disability syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.786

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PIGONM_032634.4 linkc.737C>T p.Pro246Leu missense_variant Exon 4 of 11 ENST00000378617.4 NP_116023.2 Q8TEQ8-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PIGOENST00000378617.4 linkc.737C>T p.Pro246Leu missense_variant Exon 4 of 11 1 NM_032634.4 ENSP00000367880.3 Q8TEQ8-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152172
Hom.:
0
Cov.:
33
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251430
AF XY:
0.00000736
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:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000616
AC:
9
AN:
1461844
Hom.:
0
Cov.:
32
AF XY:
0.00000825
AC XY:
6
AN XY:
727224
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39692
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
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:
0.00000719
AC:
8
AN:
1111984
Other (OTH)
AF:
0.00
AC:
0
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.00000657
AC:
1
AN:
152172
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74340
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41434
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68024
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.000132
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Apr 24, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.737C>T (p.P246L) alteration is located in exon 4 (coding exon 3) of the PIGO gene. This alteration results from a C to T substitution at nucleotide position 737, causing the proline (P) at amino acid position 246 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Hyperphosphatasia with intellectual disability syndrome 2 Uncertain:1
May 02, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 246 of the PIGO protein (p.Pro246Leu). This variant is present in population databases (no rsID available, gnomAD 0.002%). This variant has not been reported in the literature in individuals affected with PIGO-related conditions. 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: "Probably Damaging"; Align-GVGD: "Class C0"). 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
0.085
BayesDel_addAF
Pathogenic
0.25
D
BayesDel_noAF
Uncertain
0.12
CADD
Pathogenic
29
DANN
Uncertain
1.0
DEOGEN2
Benign
0.30
.;.;T
Eigen
Pathogenic
0.94
Eigen_PC
Pathogenic
0.94
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.98
.;D;D
M_CAP
Uncertain
0.10
D
MetaRNN
Pathogenic
0.79
D;D;D
MetaSVM
Uncertain
0.23
D
MutationAssessor
Pathogenic
2.9
M;M;M
PhyloP100
9.9
PrimateAI
Uncertain
0.57
T
PROVEAN
Pathogenic
-6.3
D;D;D
REVEL
Uncertain
0.59
Sift
Uncertain
0.0020
D;D;D
Sift4G
Uncertain
0.021
D;D;D
Polyphen
1.0
D;D;P
Vest4
0.75
MutPred
0.50
Loss of ubiquitination at K251 (P = 0.0298);Loss of ubiquitination at K251 (P = 0.0298);Loss of ubiquitination at K251 (P = 0.0298);
MVP
0.94
MPC
0.65
ClinPred
0.99
D
GERP RS
5.8
Varity_R
0.55
gMVP
0.82
Mutation Taster
=24/76
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: rs746364157; hg19: chr9-35093940; API