Isolated Methylmalonic Acidemia Partially Deficient Or B12 Responsive Cn381151
A metabolic disorder affecting the body's ability to break down certain proteins and fats. It can be inherited from birth. Treatment includes special diets, vitamin B12 supplementation when responsive, and close metabolic monitoring.
Key facts at a glance
- ICD-10
- E88.9
- ICD-11
- 5A00.0
- Body system
- metabolic
- Severity
- moderate
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Warning signs - seek immediate care
Metabolic acidosis
Seizures
Fatigue or weight changes
(metabolic)Noticeable symptoms that may vary in intensity over time.
Frequency: Common at all stages
Developmental delay
(neurological)Vomiting
(gastrointestinal)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
Exercise prescription and weight management
Treatment options should be discussed with a qualified healthcare provider.
Vitamin B12 Supplementation
Parenteral or high-dose oral cyanocobalamin or methylcobalamin supplementation to overcome metabolic block. Hydroxocobalamin injections are often preferred for better retention.
Protein-Restricted Metabolic Diet
Carefully controlled protein intake using specialized metabolic formulas and natural foods low in propionate precursors. Regular monitoring of amino acid levels to ensure adequacy while maintaining metabolic control.
Additional treatment options
L-Carnitine Supplementation
Carnitine replacement to support fatty acid oxidation and enhance excretion of toxic acylcarnitine intermediates. Helps prevent secondary carnitine deficiency common in organic acidemias.
medicationMetabolic and Biochemical Monitoring
Regular measurement of methylmalonic acid, homocysteine, acylcarnitine profile, and complete blood counts. Essential for tracking disease control and adjusting therapy.
monitoringGenetic Counseling Services
Comprehensive genetic counseling for patients and families including inheritance patterns, recurrence risks, prenatal testing options, and carrier testing for at-risk relatives.
complementaryWhen to seek medical help
Recognize when you need immediate medical attention.
Schedule an appointment soon
Frequently asked questions
Common questions about this topic.
What is Isolated Methylmalonic Acidemia Partially Deficient Or B12 Responsive Cn381151?
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.
Huemer C, Dobbelaere D, Lund AM. Guidelines for the diagnosis and management of isolated methylmalonic acidemia. Orphanet J Rare Dis. 2022.
Manoli I, Sloan JL, Venditti CP. Isolated methylmalonic acidemia: B12 responsiveness and therapeutic approaches. Mol Genet Metab. 2021.
Fornundi A, Baumgartner MR, Haberle J. Long-term outcomes in methylmalonic acidemias: a clinical review. J Inherit Metab Dis. 2023.
Walter JH, MacDonald A, van Spronsen FJ. Nutritional management of methylmalonic acidemia: current perspectives. Nutrients. 2020.
Medication Comparisons
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Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy