9-35089103-G-A

Variant names:

• chr9-35089103-G-A
• rs768738759
• NM_032634.4:c.3259C>T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_032634.4(PIGO):​c.3259C>T​(p.Gln1087*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,868 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: not found (cov: 33)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: PIGO NM_032634.4 stop_gained
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.16

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.00336 CDS is truncated, and there are 0 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PIGO	NM_032634.4	c.3259C>T	p.Gln1087*	stop_gained	Exon 11 of 11	ENST00000378617.4	NP_116023.2
PIGO	NM_001201484.2	c.2008C>T	p.Gln670*	stop_gained	Exon 13 of 13		NP_001188413.1
PIGO	NM_152850.4	c.2008C>T	p.Gln670*	stop_gained	Exon 12 of 12		NP_690577.2
PIGO	XM_005251619.4	c.3259C>T	p.Gln1087*	stop_gained	Exon 11 of 11		XP_005251676.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PIGO	ENST00000378617.4	c.3259C>T	p.Gln1087*	stop_gained	Exon 11 of 11	1	NM_032634.4	ENSP00000367880.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461868 Hom.: 0 Cov.: 34 AF XY: 0.00000413 AC XY: 3 AN XY: 727234

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000629

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Oct 04, 2018

Athena Diagnostics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hyperphosphatasia with intellectual disability syndrome 2 Uncertain:1

Jun 15, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change results in a premature translational stop signal in the PIGO gene (p.Gln1087*). While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 3 amino acids of the PIGO protein. This variant is present in population databases (rs768738759, ExAC 0.001%). This variant has not been reported in the literature in individuals with PIGO-related conditions. ClinVar contains an entry for this variant (Variation ID: 805131). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. 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
BayesDel_addAF	Pathogenic	0.61	D
BayesDel_noAF	Pathogenic	0.63
CADD	Pathogenic	36
DANN	Uncertain	0.99
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.77
FATHMM_MKL	Pathogenic	0.98	D
Vest4		0.25
GERP RS		4.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

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

LitVar

Other links and lift over

dbSNP: rs768738759; hg19: chr9-35089100;