BBOX1
Chr 11gamma-butyrobetaine hydroxylase 1
Also known as: BBH, BBOX, G-BBH, gamma-BBH
The protein gamma butyrobetaine hydroxylase catalyzes the final step in L-carnitine biosynthesis, converting gamma-butyrobetaine to L-carnitine, which is essential for transporting fatty acids into mitochondria for beta-oxidation. Mutations cause carnitine deficiency, secondary, which follows autosomal recessive inheritance and affects fatty acid metabolism. The gene shows extremely high constraint against loss-of-function variants (pLI near 1), indicating that complete loss of function is likely incompatible with normal development.
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Mild missense constraint
ClinVar Variant Classifications
102 submitted variants in ClinVar
Classification Summary
Curated Variants Distribution
Classified variants from ClinVar · 5 ACMG categories
| Classification | LoF | Missense + Inframe | Non-coding | Synonymous | Total |
|---|---|---|---|---|---|
Pathogenic | 0 | 0 | 19 | 0 | 19 |
Likely Pathogenic | 0 | 0 | 1 | 0 | 1 |
VUS | 0 | 56 | 12 | 0 | 68 |
Likely Benign | 0 | 0 | 0 | 1 | 1 |
Benign | 0 | 0 | 0 | 3 | 3 |
| Total | 0 | 56 | 32 | 4 | 92 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
BBOX1 · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
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