PIGX

Chr 3

phosphatidylinositol glycan anchor biosynthesis class X

Also known as: PIG-X

This gene encodes a stabilizing subunit of the glycosylphosphatidylinositol-mannosyltransferase I complex, which catalyzes the transfer of the first mannose during GPI-anchor biosynthesis in the endoplasmic reticulum. Mutations cause congenital disorders of glycosylation with early infantile epileptic encephalopathy, inherited in an autosomal recessive pattern. The gene shows tolerance to loss-of-function variants (LOEUF 1.162), suggesting that complete loss of function may be compatible with survival but still pathogenic when present in homozygous or compound heterozygous states.

OMIMResearchSummary from RefSeq, UniProt
LOEUF 1.16
Clinical SummaryPIGX
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
📋
ClinVar Variants
87 unique Pathogenic / Likely Pathogenic· 20 VUS of 122 total submissions
Some data sources returned errors (1)

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Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
1.16LOEUF
pLI 0.000
Z-score 1.14
OE 0.67 (0.401.16)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
1.16Z-score
OE missense 0.71 (0.600.85)
92 obs / 129.0 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.67 (0.401.16)
00.351.4
Missense OE0.71 (0.600.85)
00.61.4
Synonymous OE0.82
01.21.6
LoF obs/exp: 9 / 13.5Missense obs/exp: 92 / 129.0Syn Z: 0.94

ClinVar Variant Classifications

122 submitted variants in ClinVar

Classification Summary

Pathogenic84
Likely Pathogenic3
VUS20
Likely Benign2
Benign1
Conflicting1
84
Pathogenic
3
Likely Pathogenic
20
VUS
2
Likely Benign
1
Benign
1
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories· variant type breakdown unavailable

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
84
Likely Pathogenic
3
VUS
20
Likely Benign
2
Benign
1
Conflicting
1
Total111

Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

PIGX · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →
Clinical Literature
Open Research Assistant →
Key Publications
Landmark & review papers · by relevance
PubMed
Top 2 results · since 2015Search PubMed ↗
Recent Gene-Specific Literature
Gene in title · MEDLINE · newest first
Europe PMC