TUBA1A

Chr 12AD

tubulin alpha 1a

Also known as: B-ALPHA-1, LIS3, TUBA3

This gene encodes alpha tubulin, a major component of microtubules that is predominantly expressed in differentiated neurologic cells and essential for proper neuronal migration during brain development. Heterozygous loss-of-function mutations cause autosomal dominant lissencephaly type 3 (LIS3), characterized by microcephaly, intellectual disability, and early-onset epilepsy. The pathogenic mechanism involves disrupted microtubule function leading to defective neuronal migration and abnormal cortical development.

OMIMResearchSummary from RefSeq, OMIM, UniProt, Mechanism
MultiplemechanismADLOEUF 0.321 OMIM phenotype
VCEP Guidelines: Brain MalformationsReleased
View SpecificationsClinGen Panel
Clinical SummaryTUBA1A
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Gene-Disease Validity (ClinGen)
tubulinopathy · ADDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Highly constrained gene — heterozygous loss-of-function variants are very rare in the population (pLI 0.97). One damaged copy is likely sufficient to cause disease.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Dual constrained — LoF & missense intolerant
LoF Constraint
0.32LOEUF
pLI 0.967
Z-score 3.34
OE 0.07 (0.020.32)
Highly constrained

Highly LoF-intolerant (top ~10% of genes)

Missense Constraint
5.58Z-score
OE missense 0.03 (0.010.05)
7 obs / 260.7 exp
Constrained

Extremely missense-constrained (top ~0.01%)

Observed / Expected Ratios
LoF OE0.07 (0.020.32)
00.351.4
Missense OE0.03 (0.010.05)
00.61.4
Synonymous OE1.10
01.21.6
LoF obs/exp: 1 / 15.0Missense obs/exp: 7 / 260.7Syn Z: -0.77
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveTUBA1A-related tubulinopathyOTHERAD
DN
0.4983th %ile
GOF
0.3689th %ile
LOF
0.69top 10%

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

LOFprediction above median · 1 literature citation · LOEUF 0.32
DN1 literature citation

Literature Evidence

DNOur data suggest that the TUBA1A mutations disrupting lateral interactions have pronounced dominant-negative effects on microtubule dynamics that are associated with the severe end of the lissencephaly spectrum.PMID:26493046
LOFThe diminished production of TUBA1A tubulin in R264C individuals is consistent with haploinsufficiency as a cause of the disease phenotype.PMID:18199681

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312. Mechanism ranking also informed by gnomAD constraint, ClinVar, and ClinGen data.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

TUBA1A · 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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