HADHB (P55084) variants and mutations

HADHB (also known as P55084) is a human protein-coding gene encoding a trifunctional enzyme subunit beta, mitochondrial protein. It provides two enzymatic activities of the mitochondrial trifunctional complex required for long-chain fatty-acid beta-oxidation. Biallelic pathogenic variants can cause mitochondrial trifunctional-protein deficiency or long-chain 3-hydroxyacyl-CoA dehydrogenase-related disease, with cardiomyopathy, hypoglycemia, neuropathy, or rhabdomyolysis. This analysis covers 725 HADHB variants and mutations. Of these, 82% have computational variant effect predictions. Disease context includes mitochondrial trifunctional protein deficiency 2, mitochondrial trifunctional protein deficiency, and mitochondrial trifunctional protein deficiency 1. Example HADHB variants include M1V, p.Met1 Thr2insAla, and p.Thr2dup.

Variant analysis overview

Gene: HADHB
Protein: P55084
UniProt accession: P55084
Organism: Homo sapiens
Variants analyzed: 725
Variant scope: all variants
Completed: 2026-08-22

Variant and mutation evidence

Variant composition: 555 unspecified-consequence records; 3 in-frame insertions; 20 frameshift variants; 92 missense variants; 1 protein altering variant; 44 synonymous variants; 3 stop-gained variants; 4 splice-region variants; 1 in-frame deletions; 2 substitution
Prediction scores: 592 variants have prediction scores (82% of the analyzed set).

Clinical, disease, and population context

Disease context: 25 disease associations are represented. Top associations: mitochondrial trifunctional protein deficiency 2, mitochondrial trifunctional protein deficiency, mitochondrial trifunctional protein deficiency 1, long chain 3-hydroxyacyl-CoA dehydrogenase deficiency, neurodegenerative disease, alcohol drinking, gastrointestinal disease, complication, hereditary disease, metabolic acidosis, renal tubular acidosis, rickets.

Protein structure and variant hotspots

Protein features: 14 post-translational modification sites.
PTM context: 13 variants overlap post-translational modification sites.

Data sources

Evidence in this analysis draws on EBI Proteins Variation, UniProt, gnomAD v4, EuropePMC, 3D Hotspot Analysis, Interaction Network Analysis, Protein Data Bank, AlphaFold DB, gnomAD constraint, Open Targets, MaveDB, LitVar.

Notable HADHB variants

Examples include M1V, p.Met1 Thr2insAla, p.Thr2dup, T2I, p.Thr2 Ile3insAla, T2A, T2N, T2S. Listed records include available protein-change notation, database identifiers, clinical classifications, computational predictions, population evidence, experimental measurements, and disease context.

HADHB analysis run — HADHB (725 variants) — completed 2026-08-22