rs1249538886

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PP3_Moderate

The NM_004204.5(PIGQ):​c.885G>T​(p.Trp295Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000387 in 1,550,048 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 (★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 34)
Exomes 𝑓: 0.0000029 ( 0 hom. )

Consequence

PIGQ
NM_004204.5 missense

Scores

5
10
4

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.54

Publications

0 publications found
Variant links:
Genes affected
PIGQ (HGNC:14135): (phosphatidylinositol glycan anchor biosynthesis class Q) This gene is involved in the first step in glycosylphosphatidylinositol (GPI)-anchor biosynthesis. The GPI-anchor is a glycolipid found on many blood cells and serves to anchor proteins to the cell surface. This gene encodes a N-acetylglucosaminyl transferase component that is part of the complex that catalyzes transfer of N-acetylglucosamine (GlcNAc) from UDP-GlcNAc to phosphatidylinositol (PI). Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jun 2012]
PIGQ Gene-Disease associations (from GenCC):
  • developmental and epileptic encephalopathy, 77
    Inheritance: AR Classification: STRONG, MODERATE, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
  • genetic developmental and epileptic encephalopathy
    Inheritance: AD 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 2 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.891

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PIGQNM_004204.5 linkc.885G>T p.Trp295Cys missense_variant Exon 4 of 11 ENST00000321878.10 NP_004195.2
PIGQNM_148920.4 linkc.885G>T p.Trp295Cys missense_variant Exon 4 of 10 NP_683721.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PIGQENST00000321878.10 linkc.885G>T p.Trp295Cys missense_variant Exon 4 of 11 1 NM_004204.5 ENSP00000326674.6

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152252
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000286
AC:
4
AN:
1397796
Hom.:
0
Cov.:
34
AF XY:
0.00000145
AC XY:
1
AN XY:
689552
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
31650
American (AMR)
AF:
0.00
AC:
0
AN:
35742
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25168
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35792
South Asian (SAS)
AF:
0.00
AC:
0
AN:
79254
European-Finnish (FIN)
AF:
0.0000211
AC:
1
AN:
47488
Middle Eastern (MID)
AF:
0.000176
AC:
1
AN:
5674
European-Non Finnish (NFE)
AF:
0.00000185
AC:
2
AN:
1079034
Other (OTH)
AF:
0.00
AC:
0
AN:
57994
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.438
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

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:
0.0000131
AC:
2
AN:
152252
Hom.:
0
Cov.:
34
AF XY:
0.0000134
AC XY:
1
AN XY:
74376
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.0000241
AC:
1
AN:
41464
American (AMR)
AF:
0.0000654
AC:
1
AN:
15292
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68046
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.0296732), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.400
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:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

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

Submissions by phenotype

Epilepsy Uncertain:1
Feb 08, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces tryptophan, which is neutral and slightly polar, with cysteine, which is neutral and slightly polar, at codon 295 of the PIGQ protein (p.Trp295Cys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with PIGQ-related conditions. ClinVar contains an entry for this variant (Variation ID: 526271). 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. 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
Pathogenic
0.73
BayesDel_addAF
Pathogenic
0.25
D
BayesDel_noAF
Uncertain
0.12
CADD
Pathogenic
28
DANN
Uncertain
0.99
DEOGEN2
Benign
0.23
.;.;.;T
Eigen
Uncertain
0.55
Eigen_PC
Uncertain
0.52
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.91
.;D;D;D
M_CAP
Uncertain
0.28
D
MetaRNN
Pathogenic
0.89
D;D;D;D
MetaSVM
Benign
-0.36
T
MutationAssessor
Benign
1.8
L;L;.;L
PhyloP100
7.5
PrimateAI
Uncertain
0.67
T
PROVEAN
Pathogenic
-5.3
D;D;D;D
REVEL
Uncertain
0.47
Sift
Uncertain
0.0030
D;D;D;D
Sift4G
Uncertain
0.0040
D;D;D;D
Polyphen
1.0
D;D;.;D
Vest4
0.90
MutPred
0.77
Loss of catalytic residue at L293 (P = 0.0036);Loss of catalytic residue at L293 (P = 0.0036);Loss of catalytic residue at L293 (P = 0.0036);Loss of catalytic residue at L293 (P = 0.0036);
MVP
0.79
MPC
0.76
ClinPred
0.99
D
GERP RS
5.2
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.62
gMVP
0.78
Mutation Taster
=27/73
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.040
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: rs1249538886; hg19: chr16-626197; API