PCYT2

Chr 17AR

phosphate cytidylyltransferase 2, ethanolamine

Also known as: ET, SPG82

This enzyme catalyzes the formation of CDP-ethanolamine from CTP and phosphoethanolamine in the Kennedy pathway, which is essential for synthesizing phosphatidylethanolamine, a major membrane phospholipid. Mutations cause spastic paraplegia 82, an autosomal recessive disorder affecting the corticospinal tracts and causing progressive lower limb spasticity. The gene shows moderate constraint against loss-of-function variants (LOEUF 0.702), suggesting some tolerance to complete protein loss.

OMIMResearchSummary from RefSeq, OMIM, UniProt
LOFmechanismARLOEUF 0.701 OMIM phenotype
Clinical SummaryPCYT2
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
0.70LOEUF
pLI 0.001
Z-score 2.62
OE 0.40 (0.240.70)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
1.73Z-score
OE missense 0.69 (0.610.78)
169 obs / 245.2 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.40 (0.240.70)
00.351.4
Missense OE0.69 (0.610.78)
00.61.4
Synonymous OE1.09
01.21.6
LoF obs/exp: 9 / 22.4Missense obs/exp: 169 / 245.2Syn Z: -0.74
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitivePCYT2-related complex hereditary spastic paraplegiaLOFAR

Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.

DN
0.7132th %ile
GOF
0.75top 25%
LOF
0.2775th %ile

The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

PCYT2 · 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.

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Clinical Literature
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