Abstract

Maple syrup urine disease (MSUD) is an autosomal recessive genetic disorder caused by a deficiency of branched-chain alpha-ketoacid dehydrogenase (BCKAD). This condition results in the accumulation of branched-chain amino acids (BCAAs): leucine, isoleucine and valine. With five recognized clinical variants, the disease varies in severity and the clinical spectrum is quite broad. The classic form of MSUD can be recognized by the characteristic odor of maple syrup in the cerumen at 12 to 24 hours and in the urine at 48 to 72 hours after birth. Following the introduction of extended neonatal screening, cases of the disease are being detected earlier and treatment is being initiated before the onset of symptoms. However, this clinical case presents an intermittent form of MSUD newly diagnosed in a 7-year-old child with signs of metabolic intoxication and encephalopathy. The diagnosis was difficult as other conditions were more likely due to the postnatal placement of the ventriculoperitoneal shunt and the lack of detection of maple syrup smell in the urine. Treatment with diuretics and a protein-free diet significantly improved the child’s condition. Further management includes restriction of branched-chain amino acid intake and regular metabolic monitoring.

Keywords:Maple syrup urine disease (MSUD); Branched-chain amino acids (BCAAs); Branched-chain alpha-ketoacid dehydrogenase (BCKAD); Intermittent form of MSUD

Abbreviations: MSUD: Maple Syrup Urine Disease; BCAAs: Branched-Chain Amino Acids; BCKAD: Branched-Chain Alpha-Ketoacid Dehydrogenase; CT: Computed Tomography; TMA: Territorial Medical Association; EEG: Electroencephalography; CMV: Cytomegalovirus; EBV: Epstein-Barr virus; MRI: Magnetic Resonance Imaging; ECG: Electrocardiogram