4-516045-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2PP3_ModeratePP5

The NM_001127178.3(PIGG):​c.974C>T​(p.Pro325Leu) variant causes a missense change. The variant allele was found at a frequency of 0.0000558 in 1,614,052 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P325R) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000060 ( 0 hom. )

Consequence

PIGG
NM_001127178.3 missense

Scores

4
11
4

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:2

Conservation

PhyloP100: 4.81

Publications

1 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 5 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.856
PP5
Variant 4-516045-C-T is Pathogenic according to our data. Variant chr4-516045-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1195745.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PIGGNM_001127178.3 linkc.974C>T p.Pro325Leu missense_variant Exon 6 of 13 ENST00000453061.7 NP_001120650.1 Q5H8A4-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PIGGENST00000453061.7 linkc.974C>T p.Pro325Leu missense_variant Exon 6 of 13 1 NM_001127178.3 ENSP00000415203.2 Q5H8A4-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152228
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
251490
AF XY:
0.0000368
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000352
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000602
AC:
88
AN:
1461824
Hom.:
0
Cov.:
31
AF XY:
0.0000619
AC XY:
45
AN XY:
727220
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000755
AC:
84
AN:
1111954
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.461
Heterozygous variant carriers
0
5
10
16
21
26
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:
0.0000131
AC:
2
AN:
152228
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74382
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41454
American (AMR)
AF:
0.00
AC:
0
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5204
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68038
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.550
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000189
ExAC
AF:
0.0000330
AC:
4
Asia WGS
AF:
0.000289
AC:
1
AN:
3478
EpiCase
AF:
0.0000545
EpiControl
AF:
0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Pathogenic:1
Dec 04, 2024
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); 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 -

Inborn genetic diseases Uncertain:1
Feb 07, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.974C>T (p.P325L) alteration is located in exon 6 (coding exon 6) of the PIGG gene. This alteration results from a C to T substitution at nucleotide position 974, causing the proline (P) at amino acid position 325 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Intellectual disability, autosomal recessive 53 Uncertain:1
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 proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 325 of the PIGG protein (p.Pro325Leu). This variant is present in population databases (rs746660978, gnomAD 0.006%). 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: 1195745). 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: "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
0.18
BayesDel_addAF
Uncertain
0.087
D
BayesDel_noAF
Uncertain
0.060
CADD
Benign
23
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.42
.;T;D;.;.;.
Eigen
Uncertain
0.36
Eigen_PC
Uncertain
0.26
FATHMM_MKL
Uncertain
0.90
D
LIST_S2
Uncertain
0.96
D;D;D;D;D;D
M_CAP
Benign
0.029
D
MetaRNN
Pathogenic
0.86
D;D;D;D;D;D
MetaSVM
Benign
-0.59
T
MutationAssessor
Pathogenic
3.9
H;H;.;.;.;.
PhyloP100
4.8
PrimateAI
Uncertain
0.52
T
PROVEAN
Pathogenic
-8.8
D;D;D;D;D;D
REVEL
Uncertain
0.47
Sift
Pathogenic
0.0
D;D;D;D;D;D
Sift4G
Uncertain
0.0030
D;D;D;D;D;D
Polyphen
1.0
D;D;.;D;D;D
Vest4
0.84
MutPred
0.63
Gain of catalytic residue at P325 (P = 0.0668);Gain of catalytic residue at P325 (P = 0.0668);.;.;.;.;
MVP
0.57
MPC
0.68
ClinPred
1.0
D
GERP RS
4.6
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.62
gMVP
0.85
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: rs746660978; hg19: chr4-509834; COSMIC: COSV56321968; COSMIC: COSV56321968; API