NM_176787.5:c.1694G>A

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PM5PP3

The NM_176787.5(PIGN):​c.1694G>A​(p.Arg565His) variant causes a missense change. The variant allele was found at a frequency of 0.00013 in 1,608,100 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. R565L) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000079 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00014 ( 0 hom. )

Consequence

PIGN
NM_176787.5 missense

Scores

13
5
1

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 6.18

Publications

7 publications found
Variant links:
Genes affected
PIGN (HGNC:8967): (phosphatidylinositol glycan anchor biosynthesis class N) This gene encodes a protein that is involved 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 protein is expressed in the endoplasmic reticulum and transfers phosphoethanolamine (EtNP) to the first mannose of the GPI anchor. Two alternatively spliced variants, which encode an identical isoform, have been reported. [provided by RefSeq, Jul 2008]
PIGN Gene-Disease associations (from GenCC):
  • multiple congenital anomalies-hypotonia-seizures syndrome 1
    Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P, Orphanet, ClinGen, PanelApp Australia
  • Fryns 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 5 ACMG points.

PM1
In a topological_domain Lumenal (size 0) in uniprot entity PIGN_HUMAN
PM5
Other missense variant is known to change same aminoacid residue: Variant chr18-62106862-C-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 391067.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.778

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PIGNNM_176787.5 linkc.1694G>A p.Arg565His missense_variant Exon 19 of 31 ENST00000640252.2 NP_789744.1 O95427A0A024R2C3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PIGNENST00000640252.2 linkc.1694G>A p.Arg565His missense_variant Exon 19 of 31 1 NM_176787.5 ENSP00000492233.1 O95427
PIGNENST00000400334.7 linkc.1694G>A p.Arg565His missense_variant Exon 18 of 30 1 ENSP00000383188.2 O95427
PIGNENST00000638424.1 linkn.1694G>A non_coding_transcript_exon_variant Exon 17 of 29 5 ENSP00000491963.1 A0A1W2PQZ1

Frequencies

GnomAD3 genomes
AF:
0.0000855
AC:
13
AN:
151966
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000483
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000197
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000578
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.000190
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000960
AC:
23
AN:
239518
AF XY:
0.000123
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000595
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000472
Gnomad NFE exome
AF:
0.000130
Gnomad OTH exome
AF:
0.000511
GnomAD4 exome
AF:
0.000135
AC:
197
AN:
1456016
Hom.:
0
Cov.:
31
AF XY:
0.000140
AC XY:
101
AN XY:
723616
show subpopulations
African (AFR)
AF:
0.0000300
AC:
1
AN:
33374
American (AMR)
AF:
0.0000908
AC:
4
AN:
44030
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25978
East Asian (EAS)
AF:
0.0000254
AC:
1
AN:
39432
South Asian (SAS)
AF:
0.0000707
AC:
6
AN:
84878
European-Finnish (FIN)
AF:
0.000207
AC:
11
AN:
53138
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.000148
AC:
164
AN:
1109220
Other (OTH)
AF:
0.000166
AC:
10
AN:
60202
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.462
Heterozygous variant carriers
0
11
22
34
45
56
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:
0.0000789
AC:
12
AN:
152084
Hom.:
0
Cov.:
32
AF XY:
0.0000538
AC XY:
4
AN XY:
74326
show subpopulations
African (AFR)
AF:
0.0000482
AC:
2
AN:
41496
American (AMR)
AF:
0.000196
AC:
3
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000387
AC:
2
AN:
5174
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4818
European-Finnish (FIN)
AF:
0.000190
AC:
2
AN:
10548
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
67988
Other (OTH)
AF:
0.00
AC:
0
AN:
2108
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.517
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

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:
0.000118
Hom.:
0
Bravo
AF:
0.0000642
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000122
AC:
1
ExAC
AF:
0.0000829
AC:
10

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Multiple congenital anomalies-hypotonia-seizures syndrome 1 Uncertain:2
Oct 24, 2022
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 histidine, which is basic and polar, at codon 565 of the PIGN protein (p.Arg565His). This variant is present in population databases (rs201835155, gnomAD 0.01%). This missense change has been observed in individual(s) with PIGN-related disease (PMID: 32220244). ClinVar contains an entry for this variant (Variation ID: 472213). 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 PIGN protein function. 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. -

Apr 10, 2018
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -

Inborn genetic diseases Uncertain:1
Sep 02, 2016
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R565H variant (also known as c.1694G>A), located in coding exon 16 of the PIGN gene, results from a G to A substitution at nucleotide position 1694. The arginine at codon 565 is replaced by histidine, an amino acid with highly similar properties. This variant was previously reported in the SNPDatabase as rs201835155. Based on data from the NHLBI Exome Sequencing Project (ESP), the A allele has an overall frequency of approximately 0.01% (1/11946) total alleles studied and 0.01% (1/8198) European American alleles. Allele frequency data for this nucleotide position is not currently available from the 1000 Genomes Project. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this variant remains unclear. -

not provided Uncertain:1
Apr 15, 2025
GeneDx
Significance:Uncertain significance
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; Identified with additional PIGN variants on the same allele (in cis) and on the opposite allele (in trans) in a patient with seizures, hypotonia, dysmorphic features, and abnormal brain MRI (PMID: 32220244); This variant is associated with the following publications: (PMID: 34426522, 32220244) -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.70
BayesDel_addAF
Pathogenic
0.20
D
BayesDel_noAF
Pathogenic
0.29
CADD
Pathogenic
30
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.56
D;.;D;D;D;.;.;.;.;.;D;.;.;D;.;D;.;.
Eigen
Pathogenic
0.98
Eigen_PC
Pathogenic
0.93
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Pathogenic
0.99
.;.;.;.;.;.;D;.;D;D;.;D;D;.;D;D;D;D
M_CAP
Uncertain
0.13
D
MetaRNN
Pathogenic
0.78
D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM
Uncertain
0.24
D
MutationAssessor
Pathogenic
3.4
M;.;M;M;M;.;.;.;.;.;M;.;.;M;.;M;.;.
PhyloP100
6.2
PrimateAI
Uncertain
0.54
T
PROVEAN
Pathogenic
-4.8
.;.;.;D;.;.;.;.;.;.;D;.;.;.;.;.;.;.
REVEL
Pathogenic
0.67
Sift
Uncertain
0.0010
.;.;.;D;.;.;.;.;.;.;D;.;.;.;.;.;.;.
Sift4G
Pathogenic
0.0
.;.;.;D;.;.;.;.;.;.;D;.;.;.;.;.;.;.
Polyphen
1.0
D;.;D;D;D;.;.;.;.;.;D;.;.;D;.;D;.;.
Vest4
0.90
MVP
0.88
MPC
0.21
ClinPred
0.98
D
GERP RS
6.1
Varity_R
0.71
gMVP
0.92
Mutation Taster
=17/83
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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: rs201835155; hg19: chr18-59774095; COSMIC: COSV62949229; COSMIC: COSV62949229; API