Journal Article

A rare cause of severe diarrhoea diagnosed by urine metabolic screening: aromatic L-amino acid decarboxylase deficiency

Cheng, WW, Ko, CH, Lee, LK, Lee, Hencher HC, Cheung, KM, Ching, CK, Mak, Chloe M

2014

Overview

A 15-year-old Chinese male with infantile-onset hypotonia, developmental delay, ptosis, and oculogyric episodes presented with a history of chronic diarrhoea since the age of 5 years. At presentation, he had an exacerbation of diarrhoeal symptoms resulting in dehydration and malnutrition with a concurrent severe chest infection. In view of his infantile-onset hypotonia, oculogyric crises, and protracted diarrhoea, an autonomic disturbance related to neurotransmitters was suspected. Urine organic acid profiling was compatible with aromatic L-amino acid decarboxylase deficiency. The diagnosis was confirmed based on cerebrospinal fluid analysis and genetic mutation analysis. The patient was treated with a combination of bromocriptine, selegiline, and pyridoxine; a satisfactory reduction in diarrhoea ensued. Our report highlights the importance of urine organic acid screening in infantile-onset hypotonia, especially when accompanied by oculogyric crises, and severe diarrhoea which could manifest as a result of autonomic disturbance.

• Publisher: Hong Kong Academy of Medicine
• Subject: Adolescent / Age / Amino Acid Metabolism, Inborn Errors - complications / Amino Acid Metabolism, Inborn Errors - diagnosis / Amino acids / Aromatic-L-Amino-Acid Decarboxylases - deficiency / Biopsy / Cardiac arrhythmia / Case reports / Cerebrospinal fluid / Cysts / Developmental Disabilities - complications / Diarrhea / Diarrhea - etiology / Dopamine / Electrolytes / Humans / Hypotension / Male / Metabolism / Muscle Hypotonia - complications / Muscle Hypotonia - congenital / Mutation / Ocular Motility Disorders - complications / Ocular Motility Disorders - congenital / Ostomy / Patients / Pleural effusion / Pneumonia / Potassium / Severity of Illness Index / Urine