FB2026_03 , released September 17, 2026
Human Disease Model Report: HIBCH deficiency
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General Information
Name
HIBCH deficiency
FlyBase ID
FBhh0001630
Disease Ontology Term
Parent Disease
Overview

This report describes HIBCH deficiency (3-hydroxyisobutryl-CoA hydrolase deficiency; HIBCHD). HIBCHD exhibits autosomal recessive inheritance. The human HIBCH gene encodes a protein that localizes to mitochondria and functions in valine catabolism. There is a single orthologous gene in Drosophila, Dmel\Hibch, for which a number of genetic reagents have been generated, including a knockout allele and a variant analogous to a human variant implicated in this disease (see the 'Disease-Implicated Variants' table below.

A UAS construct of the wild-type human gene, Hsap\HIBCH, has been introduced into flies, but has not been characterized in the context of this disease.

Animals homozygous for a knockout allele of Dmel\Hibch typically die during the third larval instar stage; larval fat bodies exhibit elevated lysine methacrylation. Mosaic expression of the knockout Hibch allele in the developing eye results in progressive degeneration visible in the adult eye. Co-expression of the wild-type Hibch gene rescues the eye phenotype; co-expression of the Hibch gene carrying a mutation analogous to a disease-implicated human variant does not rescue. The Drosophila model has been used to assess the efficacy of potential therapeutic compounds.

[updated May 2025 by FlyBase; FBrf0222196]

Disease Summary Information
Disease Summary: HIBCH deficiency
OMIM report

[3-HYDROXYISOBUTYRYL-CoA HYDROLASE DEFICIENCY; HIBCHD](https://omim.org/entry/250620)

Human gene(s) implicated

[3-HYDROXYISOBUTYRYL-CoA HYDROLASE; HIBCH](https://omim.org/entry/610690)

Symptoms and phenotype

HIBCHD) is an autosomal recessive inborn error of metabolism characterized by severely delayed psychomotor development, neurodegeneration, increased lactic acid, and brain lesions in the basal ganglia (summary by Ferdinandusse et al., 2013; pubmed:24299452). [from MIM:250620; 2025.05.14]

Genetics

3-hydroxyisobutyryl-CoA hydrolase deficiency (HIBCHD) is caused by homozygous or compound heterozygous mutation in the HIBCH gene. [from MIM:250620; 2025.05.14]

Cellular phenotype and pathology
Molecular information

HIBCH, like ECHS1, encodes an enzyme localized to mitochondria. In the valine catabolic pathway, ECHS1 is immediately upstream of HIBCH and catalyzes the conversion of methacrylyl-CoA to 3-hydroxyisobutyryl-CoA. HIBCH catalyzes the conversion of 3-hydroxyisobutyryl-CoA to free 3-hydroxyisobutyrate. Methacrylyl-CoA, a highly reactive metabolite, accumulates in ECHS1 or HIBCH deficiency (Li et al., 2025, pubmed:40056416; and references cited therein).

External links
Disease synonyms
3-hydroxyisobutryl-CoA hydrolase deficiency
HIBCHD
methacrylic aciduria
valine metabolic defect
Ortholog Information
Human gene(s) in FlyBase
Human gene (HGNC)
D. melanogaster ortholog (based on DIOPT)
Comments on ortholog(s)

One to one: 1 human gene to 1 Drosophila gene.

Other mammalian ortholog(s) used
    D. melanogaster Gene Information (1)
    Cellular component (GO)
    Gene Groups / Pathways
    Comments on ortholog(s)

    High-scoring ortholog of human HIBCH (1 Drosophila to 1 human).

    Orthologs and Alignments from DRSC
    DIOPT - DRSC Integrative Ortholog Prediction Tool - Click the link below to search for orthologs in Humans
    Other Genes Used: Viral, Bacterial, Synthetic (0)
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      Alleles Reported to Model Human Disease (Disease Ontology) (1 alleles)
      Models Based on Experimental Evidence ( 1 )
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      Genetic Tools, Stocks and Reagents
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      Contact lab of origin for a reagent not available from a public stock center.
      Bloomington Stock Center Disease Page
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      References (6)