rs773937388

Variant names:

• chr9-35095242-C-A
• rs773937388
• NM_032634.4:c.324G>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_032634.4(PIGO):​c.324G>T​(p.Gln108His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,874 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: PIGO NM_032634.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.0120
• Publications: 1 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.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.05828631).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PIGO	NM_032634.4	c.324G>T	p.Gln108His	missense_variant	Exon 2 of 11	ENST00000378617.4	NP_116023.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PIGO	ENST00000378617.4	c.324G>T	p.Gln108His	missense_variant	Exon 2 of 11	1	NM_032634.4	ENSP00000367880.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000795 AC: 2 AN: 251446 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461874 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727240

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

American (AMR) AF: 0.0000447 AC: 2 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111998

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hyperphosphatasia with intellectual disability syndrome 2 Uncertain:1

Oct 18, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. 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, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with PIGO-related disease. This variant is present in population databases (rs773937388, ExAC 0.009%). This sequence change replaces glutamine with histidine at codon 108 of the PIGO protein (p.Gln108His). The glutamine residue is moderately conserved and there is a small physicochemical difference between glutamine and histidine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Benign	-0.41	T
BayesDel_noAF	Benign	-0.65
CADD	Benign	4.3
DANN	Benign	0.69
DEOGEN2	Benign	0.030	.;.;T
Eigen	Benign	-0.91
Eigen_PC	Benign	-0.78
FATHMM_MKL	Benign	0.70	D
LIST_S2	Benign	0.54	.;T;T
M_CAP	Benign	0.0023	T
MetaRNN	Benign	0.058	T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	-0.13	N;N;N
PhyloP100		0.012
PrimateAI	Benign	0.38	T
PROVEAN	Benign	1.1	N;N;N
REVEL	Benign	0.084
Sift	Benign	1.0	T;T;T
Sift4G	Benign	0.70	T;T;T
Polyphen		0.0	B;B;B
Vest4		0.10
MutPred		0.60		Gain of helix (P = 0.0696);Gain of helix (P = 0.0696);Gain of helix (P = 0.0696);
MVP		0.19
MPC		0.14
ClinPred		0.089	T
GERP RS		-0.28
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.028
gMVP		0.62
Mutation Taster		=87/13	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs773937388; hg19: chr9-35095239;