Six Patients with Methylmalonic Acidemia and Their Outcome: Literature Review and Case Series

Document Type : Case Report


1 Department of Pediatrics, Shahid Sadoughi University of Medical Sciences, Yazd, Iran

2 Department of Clinical Biochemistry, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran

3 Department of Pediatrics, Shahid sadoughi University of Medical Sciences, Yazd, Iran


Background: Methylmalonic acidemia (MMA) is a congenital disorder due to the defects in the propionate pathway. It results from a deficiency in methylmalonyl coenzyme A mutase or one of the steps of the synthesis of the cobalamin (B12) cofactors for the enzyme. There is deficiency of methylmalonyl coA mutase (MCM) in the classic MMA.It presents with severe metabolic acidosis in the first month of life, progressive failure to thrive, feeding problems, recurrent vomiting, dehydration, hepatomegaly, lethargy, seizures, and developmental delay. Quantitative analysis of urinary organic acid patterns by GC-MS is used in MMA diagnosis. Treatment with large doses of hydroxocobalamin is helpful in some cases of MMA.
Case Presentation: We Reported 6 patients with MMA with a variety of clinical manifestations and outcomes.
Conclusion: The overall prognosis of classic MMA remains doubtful, whereas vitamin B12 responsive MMA has a reasonable outcome.


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