Clinical and Biochemical Profiles of Maple Syrup Urine Disease in Malaysian Children
Introduction: Maple Syrup Urine Disease (MSUD) is an autosomal recessive disorder caused by defects in the branched-chain α-ketoacid dehydrogenase complex resulting in accumulation of branched-chain amino acids (BCAAs) and corresponding branched-chain ketoacids (BCKAs) in tissues and plasma, which are neurotoxic. Early diagnosis and subsequent nutritional modification management can reduce the morbidity and mortality. Prior to 1990s, the diagnosis of MSUD and other inborn errors of metabolism (IEM) in Malaysia were merely based on clinical suspicion and qualitative one-dimensional thin layer chromatography technique. We have successfully established specific laboratory diagnostic techniques to diagnose MSUD and other IEM. We described here our experience in performing high-risk screening for IEM in Malaysia from 1999 to 2006. We analysed the clinical and biochemical profiles of 25 patients with MSUD.
Methods: A total of 12,728 plasma and urine samples from patients suspected of having IEM were received from physicians all over Malaysia. Plasma amino acids quantitation using fully automated amino acid analyzer and identification of urinary organic acids using Gas Chromatography Mass Spectrometry (GCMS). Patients’ clinical information were obtained from the request forms and case records
Results: Twenty-five patients were diagnosed MSUD. Nineteen patients (76%) were affected by classical MSUD, whereas six patients had non-classical MSUD. Delayed diagnosis was common among our case series, and 80% of patients had survived with treatment with mild-to-moderate learning difficulties.
Conclusion: Our findings suggested that MSUD is not uncommon in Malaysia especially among the Malay and early laboratory diagnosis is crucial.
KeywordsPlasma Amino Acid Maple Syrup Urine Disease Maple Syrup Urine Disease Newborn Screening Programme Automate Amino Acid Analyzer
We thank the Director General of Health Malaysia for permission to publish this paper. We would also like to express our gratitude to all Biochemistry staff for their technical assistance and to Dr Zakiah Ismail for initiating the project. Our special thanks to Dr Shahnaz Murad, Director of IMR, Dr. Rohani Md Yasin, Head of Specialized Diagnostic Centre and Dr Mohd Helmi Ismail for critical reading of the manuscript and valuable comments.
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