4-539241-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_001127178.3(PIGG):​c.2824C>T​(p.Arg942Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000118 in 1,611,350 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. R942H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000069 ( 0 hom. )

Consequence

PIGG
NM_001127178.3 missense

Scores

9
7
3

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 5.05

Publications

0 publications found
Variant links:
Genes affected
PIGG (HGNC:25985): (phosphatidylinositol glycan anchor biosynthesis class G (EMM blood group)) This gene encodes an enzyme involved in glycosylphosphatidylinositol-anchor biosynthesis. The encoded protein, which is localized to the endoplasmic reticulum, is involved in transferring ethanoloamine phosphate to mannose 2 of glycosylphosphatidylinositol species H7 to form species H8. Allelic variants of this gene have been associated with intellectual disability, hypotonia, and early-onset seizures. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Sep 2016]
PIGG Gene-Disease associations (from GenCC):
  • intellectual disability, autosomal recessive 53
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.904

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PIGGNM_001127178.3 linkc.2824C>T p.Arg942Cys missense_variant Exon 13 of 13 ENST00000453061.7 NP_001120650.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PIGGENST00000453061.7 linkc.2824C>T p.Arg942Cys missense_variant Exon 13 of 13 1 NM_001127178.3 ENSP00000415203.2

Frequencies

GnomAD3 genomes
AF:
0.0000591
AC:
9
AN:
152188
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000193
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:
0.0000199
AC:
5
AN:
251424
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.000185
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000685
AC:
10
AN:
1459044
Hom.:
0
Cov.:
29
AF XY:
0.00000551
AC XY:
4
AN XY:
726012
show subpopulations
African (AFR)
AF:
0.000150
AC:
5
AN:
33410
American (AMR)
AF:
0.0000447
AC:
2
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26124
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39680
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86204
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5756
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1109428
Other (OTH)
AF:
0.00
AC:
0
AN:
60302
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.480
Heterozygous variant carriers
0
1
2
2
3
4
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:
0.0000591
AC:
9
AN:
152306
Hom.:
0
Cov.:
33
AF XY:
0.0000537
AC XY:
4
AN XY:
74484
show subpopulations
African (AFR)
AF:
0.000192
AC:
8
AN:
41562
American (AMR)
AF:
0.00
AC:
0
AN:
15300
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.492
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000357
Hom.:
0
Bravo
AF:
0.0000491
ExAC
AF:
0.0000247
AC:
3

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Intellectual disability, autosomal recessive 53 Uncertain:1
Feb 17, 2024
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 cysteine, which is neutral and slightly polar, at codon 942 of the PIGG protein (p.Arg942Cys). This variant is present in population databases (rs532389677, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with PIGG-related conditions. ClinVar contains an entry for this variant (Variation ID: 476344). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt PIGG protein function with a positive predictive value of 80%. 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
Uncertain
0.55
BayesDel_addAF
Pathogenic
0.17
D
BayesDel_noAF
Pathogenic
0.29
CADD
Pathogenic
31
DANN
Pathogenic
1.0
DEOGEN2
Benign
0.097
.;T;T;.
Eigen
Pathogenic
0.88
Eigen_PC
Pathogenic
0.82
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Uncertain
0.97
D;D;D;D
M_CAP
Benign
0.047
D
MetaRNN
Pathogenic
0.90
D;D;D;D
MetaSVM
Uncertain
0.11
D
MutationAssessor
Pathogenic
3.6
.;H;.;.
PhyloP100
5.1
PrimateAI
Uncertain
0.79
T
PROVEAN
Pathogenic
-6.9
D;D;D;D
REVEL
Uncertain
0.64
Sift
Pathogenic
0.0
D;D;D;D
Sift4G
Uncertain
0.0020
D;D;D;D
Polyphen
1.0
D;D;.;D
Vest4
0.95
MutPred
0.81
.;Loss of methylation at R942 (P = 0.0312);.;.;
MVP
0.97
MPC
0.82
ClinPred
1.0
D
GERP RS
5.9
Varity_R
0.66
gMVP
0.82
Mutation Taster
=33/67
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: rs532389677; hg19: chr4-533030; COSMIC: COSV99573546; COSMIC: COSV99573546; API