Abstract
Background: Maple syrup urine disease (MSUD) is a rare autosomal recessive metabolically inherited disorder, caused by an abnormal function of the branched-chain α-keto acid dehydrogenase complex in the mitochondria. Case Presentation: The proband was born after a full-term pregnancy and normal vaginal delivery, with a good Apgar score (8, 9 at 1 and 5 minutes) and the birth weight of 2.5 kg with ambiguous genitalia in the form of phallus-like structure (3 cm), the fusion of labio-scrotal folds and urogenital sinus. The third day after birth, the proband was lethargic and developed hyperkalemia and hyponatremia, which required intravenous fluid therapy and hormonal replacement with hydrocortisone and fludrocortisone. The treatment was based on the positive family history of congenital adrenal hyperplasia in an older male sibling. Laboratory tests, cytogenetic study, tandem mass spectroscopy, and surgery were performed for the affected individual (II-8) using standard procedures. The laboratory and the treatment revealed significant improvements. Follow-up tandem mass spectroscopy results were observed in the normal range. The affected individual was treated with prednisone (2.5 mg bid) and Florinef (Fludrocortisone) (0.1 mg OD). The subject had regular menses, while acne and hirsutism were not observed. Conclusion: We are reporting the first case of MSUD associated with CAH, 21-hydroxylase deficiency salt-losing type and suggest that glucocorticoids might have an important role in treating MSUD cases.

Key words: MSUD, 21-hydroxylase deficiency, congenital adrenal hyperplasia.