TPPP3

Chr 16

tubulin polymerization promoting protein family member 3

Also known as: CGI-38, TPPP/p20, p20, p25gamma

Enables tubulin binding activity. Involved in decidualization and microtubule bundle formation. Located in microtubule bundle and perinuclear region of cytoplasm. [provided by Alliance of Genome Resources, Jul 2025]

0
Active trials
25
Pathogenic / LP
50
ClinVar variants
7
Pubs (1 yr)
0.9
Missense Z
0.99
LOEUF
Clinical SummaryTPPP3
Population Constraint (gnomAD)
Constrained for loss-of-function variants (OE-LoF 0.21) despite low pLI — interpret in context.
📋
ClinVar Variants
25 Pathogenic / Likely Pathogenic· 25 VUS of 50 total submissions

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint?LOEUF (Loss-of-function Observed/Expected Upper bound Fraction) is the upper bound of the 90% CI for LoF OE — the preferred gnomAD v4 metric. Lower = more intolerant to LoF. LOEUF < 0.35 = highly constrained.
0.99LOEUF
pLI 0.373
Z-score 1.60
OE 0.21 (0.070.99)
Tolerant

Typical tolerance to LoF variation

Missense Constraint?Missense Z-score: standard deviations fewer missense variants observed vs. expected. Z > 3.09 (p < 0.001) = gene does not tolerate missense variation. OE missense < 0.6 is also considered constrained.
0.88Z-score
OE missense 0.77 (0.650.92)
89 obs / 115.5 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?Shaded band = 90% confidence interval. Vertical tick = point estimate. Grey threshold line = gnomAD constraint cutoff for that variant class.
LoF OE?Ratio of observed to expected LoF variants. Upper CI bound (LOEUF) ≤ 0.35 = strong LoF constraint signal.0.21 (0.070.99)
00.351.4
Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.77 (0.650.92)
00.61.4
Synonymous OE?Control metric — synonymous variants are largely neutral and expected near OE = 1.0. Significant deviation may indicate annotation issues.0.86
01.21.6
LoF obs/exp: 1 / 4.8Missense obs/exp: 89 / 115.5Syn Z: 0.74
DN
0.75top 25%
GOF
0.78top 25%
LOF
0.3550th %ile

This gene has evidence for multiple mechanisms of pathogenicity (gain-of-function and dominant-negative). Both the Badonyi & Marsh prediction and the broader genomic evidence point to gain-of-function as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

GOFprediction above median
DNprediction above median

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

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

ClinVar Variant Classifications

50 submitted variants in ClinVar

Classification Summary

Pathogenic24
Likely Pathogenic1
VUS25
24
Pathogenic
1
Likely Pathogenic
25
VUS

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
0
24
0
24
Likely Pathogenic
0
0
1
0
1
VUS
0
20
5
0
25
Likely Benign
0
0
0
0
0
Benign
0
0
0
0
0
Total02030050

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

TPPP3 · protein map & ClinVar variants

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

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →
Clinical Literature
Landmark / reviewRecent case evidence