Related Experiment Videos
Branched-chain organic acidurias
H Ogier de Baulny1, J M Saudubray
1Service de Neuropédiatrie, Maladies Métaboliques, Hôpital Robert Debré, Paris, France. helene.ogier@rdb.ap-hop-paris.fr
Seminars in Neonatology : SN
|June 19, 2002
Summary
Branched chain organic acidurias, including Maple Syrup Urine Disease, are inherited metabolic disorders affecting amino acid breakdown. Early diagnosis and treatment involving diet and carnitine are crucial for managing these conditions.
Area of Science:
- Biochemistry
- Genetics
- Pediatrics
Background:
- Branched chain organic acidurias are a group of inherited metabolic disorders.
- These conditions arise from enzyme abnormalities in branched-chain amino acid (BCAA) catabolism, specifically leucine, isoleucine, and valine.
- Common examples include Maple Syrup Urine Disease (MSUD), Isovaleric Acidaemia (IVA), Propionic Aciduria (PA), and Methylmalonic Aciduria (MMA).
Purpose of the Study:
- To summarize the clinical presentation, diagnosis, and management of common branched chain organic acidurias.
- To highlight the importance of early detection in neonates presenting with specific symptoms.
- To outline diagnostic methodologies and therapeutic strategies for these rare diseases.
Main Methods:
- Review of clinical and biochemical features of MSUD, IVA, PA, and MMA.
- Discussion of diagnostic techniques including acylcarnitine profiling and organic acid analysis in plasma and urine.
- Gas chromatography-mass spectrometry (GC-MS) and tandem mass spectrometry (MS-MS) are key diagnostic tools.
Main Results:
- These disorders typically manifest in neonates with neurological distress, ketosis/ketoacidosis, and hyperammonemia, often after a symptom-free interval.
- MMA, PA, and IVA can present with dehydration, leukoneutropenia, and thrombocytopenia, mimicking sepsis.
- Diagnostic confirmation relies on identifying specific acylcarnitine and organic acid profiles.
Conclusions:
- Branched chain organic acidurias are serious neonatal conditions requiring prompt diagnosis.
- Effective management involves dietary modifications to remove toxic metabolites and supplementation with carnitine.
- Timely intervention can significantly improve patient outcomes.