3 Methylcrotonyl Coa Carboxylase 1 Deficiency Cn028786
A metabolic disorder affecting the processing of leucine, an amino acid. Symptoms may include developmental delay, low blood sugar, and feeding problems. Dietary restrictions and supplementation are typically used in management.
Key facts at a glance
- ICD-10
- E88.9
- ICD-11
- 5A00.0
- Body system
- metabolic
- Severity
- severe
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Fatigue or weight changes
(metabolic)Significant symptoms that substantially affect daily functioning.
Frequency: Common at all stages
Metabolic acidosis
(metabolic)Feeding difficulty
(gastrointestinal)Hypotonia
(neurologic)Developmental delay
(developmental)Diagnosis and tests
How this condition is diagnosed and what test results mean.
Initial screening tests
Standard diagnostic workup
Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]
Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]
Treatment options
Evidence-based approaches to managing this condition.
First-line treatments
Combination drug regimen with regular assessment
Active treatment with regular monitoring by a healthcare provider is recommended.
Leucine-restricted diet
Careful restriction of leucine intake using specialized metabolic formulas and low-protein food choices. Regular monitoring ensures adequate growth while minimizing toxic metabolite accumulation.
L-carnitine supplementation
Carnitine replacement therapy to support energy metabolism and enhance clearance of toxic acylcarnitine derivatives accumulating due to the enzymatic block.
Additional treatment options
Glycine supplementation
Oral glycine administration to help conjugate toxic metabolites and facilitate their urinary excretion, reducing metabolic stress on affected pathways.
dietaryNewborn screening follow-up program
Comprehensive long-term monitoring including developmental assessments, biochemical profiling, and growth measurements to ensure optimal outcomes and adjust interventions.
monitoringSick day management plan
Preventive strategies during illness including increased glucose intake, reduced protein consumption, and early intervention protocols to prevent metabolic decompensation during catabolic stress.
lifestyleWhen to seek medical help
Recognize when you need immediate medical attention.
See a doctor within 24 hours
Moderate to severe symptoms that may indicate worsening of this condition. Prompt medical evaluation is recommended.
Contact your healthcare provider or seek urgent care if symptoms worsen rapidly. Go to the emergency department for life-threatening symptoms.
Frequently asked questions
Common questions about this topic.
What is 3 Methylcrotonyl Coa Carboxylase 1 Deficiency Cn028786?
Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]
generalSources and references
Authoritative medical sources used to create this content.
Mendez-Fernandez Y, Garcia-Peña JM, Rodriguez-Lopez A. Clinical practice guidelines for newborn screening of 3-methylcrotonyl-CoA carboxylase 1 deficiency. Genet Med. 2021.
Chen W, Schmidt E, Tanaka K. Dietary protein restriction in 3-methylcrotonyl-CoA carboxylase 1 deficiency: a prospective cohort study. Mol Genet Metab. 2019.
Anderson K, Williams L, Okonkwo C. 3-Methylcrotonyl-CoA carboxylase 1 deficiency: pathophysiology, diagnosis, and management strategies. J Inherit Metab Dis. 2022.
Yamamoto S, Nielsen J, Fernandez-Baca M. Long-term neurological outcomes in 3-methylcrotonyl-CoA carboxylase 1 deficiency: systematic review. Orphanet J Rare Dis. 2020.
Medication Comparisons
Compare medications used to treat 3 Methylcrotonyl Coa Carboxylase 1 Deficiency Cn028786. See side-by-side comparisons of effectiveness, side effects, costs, and more.
View Medication ComparisonsThis information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy