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Also known as:3-methylcrotonyl-CoA carboxylase deficiency caused by mutation in MCCC2MCCC2 3-methylcrotonyl-CoA carboxylase deficiency3 alpha methylcrotonyl-CoA carboxylase 2 deficiency
Overview
Any 3-methylcrotonyl-CoA carboxylase deficiency in which the cause of the disease is a mutation in the MCCC2 gene.
GeneticsAutosomal recessive · MCCC2 (chr 5)
ResearchLimited published research (8 articles)
Clinical Presentation
Built from Human Phenotype Ontology (HPO) phenotype annotations and GeneReviews clinical descriptions. Features represent findings documented across known cases — not an exhaustive list of possible symptoms.
Features include always present findings: Global developmental delay; and common findings: Decreased circulating carnitine concentration, Hyperammonemia, and Hyperleucinemia. 27 total HPO annotations.
Low muscle tone (hypotonia), Generalized hypotonia, Skeletal muscle atrophy
Skin
2
Alopecia, Seborrheic dermatitis
Bones and joints
2
Severe backward arching of the body (opisthotonus), Skeletal muscle atrophy
Digestive system
2
Vomiting, Feeding difficulties
Growth and development
1
Failure to thrive
Metabolism
1
Metabolic acidosis
Explore clinical features
Genetic Landscape
Assembled from HGNC gene records, ClinGen gene-disease validity evidence, and ClinVar pathogenic variant data. Validity classifications reflect the strength of published evidence linking each gene to this disease.
MCCC2 encodes methylcrotonyl-CoA carboxylase subunit 2 (563 aa). Carboxyltransferase subunit of the 3-methylcrotonyl-CoA carboxylase, an enzyme that catalyzes the conversion of 3-methylcrotonyl-CoA to 3-methylglutaconyl-CoA, a critical step for leucine and isovaler...
3-methylcrotonyl-CoA carboxylase 2 deficiency is associated with mutations in the MCCC2 gene on chromosome 5.
MCCC2 is classified as a druggable target (Druggable Genome and Enzyme categories) with score 0.0.
Diagnosis
Genetic testing for MCCC2 is available. Testing is considered confirmatory for diagnosis.
Prognosis
Phenotype severity distribution: 1 always present feature, 3 common features.
Research Landscape
Sourced from ClinicalTrials.gov and PubMed. Publication types are classified using NLM-curated article metadata; research type breakdowns reflect the nature of published work for this disease.
No clinical trials have been registered for 3-methylcrotonyl-CoA carboxylase 2 deficiency.
8 publications have been identified in PubMed for 3-methylcrotonyl-CoA carboxylase 2 deficiency. Research spans Case Report / Case Series (50%), Epidemiology / Natural History (38%), and Review / Meta-Analysis (13%).
Gulzar MM (2025). [PMID: 40639867](https://pubmed.ncbi.nlm.nih.gov/40639867/). *BMJ case reports*. [Case Report / Case Series]
Gragnaniello V (2025). [PMID: 41440811](https://pubmed.ncbi.nlm.nih.gov/41440811/). *International journal of neonatal screening*. [Case Report / Case Series]
Lin Y (2025). [PMID: 40835664](https://pubmed.ncbi.nlm.nih.gov/40835664/). *Scientific reports*. [Epidemiology / Natural History]
Lin W (2024). [PMID: 39188588](https://pubmed.ncbi.nlm.nih.gov/39188588/). *Molecular genetics and metabolism reports*. [Epidemiology / Natural History]
Terracciano R (2024). [PMID: 39055105](https://pubmed.ncbi.nlm.nih.gov/39055105/). *Molecular genetics and metabolism reports*. [Case Report / Case Series]
Zhang LM (2024). [PMID: 39148390](https://pubmed.ncbi.nlm.nih.gov/39148390/). *Zhongguo dang dai er ke za zhi = Chinese journal of contemporary pediatrics*. [Case Report / Case Series]
Al Mutairi F (2024). [PMID: 39484073](https://pubmed.ncbi.nlm.nih.gov/39484073/). *Molecular genetics and metabolism reports*. [Epidemiology / Natural History]
Data assembled from 5 of 12 sources · Last updated Sep 20, 2026, 8:44 AM UTC
Diseases are connected by shared genes, phenotypes, therapeutic targets, and MONDO disease hierarchy. The Rare badge reflects Kisho's rarity classification — scored from authoritative sources including OMIM, Orphanet, orphan drug designations, clinical trial activity, and published prevalence data.
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