ARL13B
Chr 3ARARF like GTPase 13B
Also known as: ARL2L1, JBTS8
This gene encodes a cilium-specific GTPase that controls the microtubule-based ciliary axoneme structure and is required for neural tube patterning and cerebral cortex development. Mutations cause Joubert syndrome 8, a ciliopathy characterized by cerebellar vermis hypoplasia and brainstem malformation, with autosomal recessive inheritance. The gene shows very low tolerance to loss-of-function variants (pLI near 0), suggesting that complete loss of function may be incompatible with survival in the heterozygous state.
Definitive — sufficient evidence for diagnostic panels
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Tolerant to missense variation
Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.
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
ARL13B · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
3D Protein StructureAlphaFold
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
No active trials found for this gene.
Search ClinicalTrials.gov →External Resources
Links to major genomics databases and tools