NM_032634.4:c.2192G>A

Variant names:

• chr9-35091695-C-T
• rs946030670
• NM_032634.4:c.2192G>A

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_032634.4(PIGO):​c.2192G>A​(p.Arg731His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000205 in 1,460,056 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign 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. R731C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000021 (0 hom.)
• Consequence: PIGO NM_032634.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.33
• Publications: 0 publications found

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

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.213483).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PIGO	NM_032634.4	c.2192G>A	p.Arg731His	missense_variant	Exon 7 of 11	ENST00000378617.4	NP_116023.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PIGO	ENST00000378617.4	c.2192G>A	p.Arg731His	missense_variant	Exon 7 of 11	1	NM_032634.4	ENSP00000367880.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.0000204 AC: 5 AN: 244726 AF XY: 0.0000299

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000220

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000166

GnomAD4 exome AF: 0.0000205 AC: 30 AN: 1460056 Hom.: 0 Cov.: 31 AF XY: 0.0000248 AC XY: 18 AN XY: 726388

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.000479 AC: 19 AN: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51622

Middle Eastern (MID) AF: 0.000173 AC: 1 AN: 5768

European-Non Finnish (NFE) AF: 0.00000629 AC: 7 AN: 1111996

Other (OTH) AF: 0.0000331 AC: 2 AN: 60372

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000301 Hom.: 0

Bravo AF: 0.0000113

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hyperphosphatasia with intellectual disability syndrome 2 Uncertain:1

Feb 06, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature in individuals affected with PIGO-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.02%). This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 731 of the PIGO protein (p.Arg731His). ClinVar contains an entry for this variant (Variation ID: 540453). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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	0.089
BayesDel_addAF	Benign	-0.15	T
BayesDel_noAF	Benign	-0.17
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Benign	0.057	T
Eigen	Benign	-0.073
Eigen_PC	Benign	0.034
FATHMM_MKL	Benign	0.68	D
LIST_S2	Benign	0.79	T
M_CAP	Benign	0.014	T
MetaRNN	Benign	0.21	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.76	N
PhyloP100		1.3
PrimateAI	Uncertain	0.58	T
PROVEAN	Benign	-1.6	N
REVEL	Benign	0.16
Sift	Uncertain	0.019	D
Sift4G	Uncertain	0.036	D
Polyphen		0.78	P
Vest4		0.26
MutPred		0.33		Loss of methylation at R731 (P = 0.0407);
MVP		0.57
MPC		0.19
ClinPred		0.19	T
GERP RS		5.4
Varity_R		0.087
gMVP		0.22
Mutation Taster		=88/12	polymorphism

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

Other links and lift over

dbSNP: rs946030670; hg19: chr9-35091692; COSMIC: COSV53054913; COSMIC: COSV53054913;