Organic acid disorders detected by urine organic acid analysis: twelve cases in Thailand over three-year experience

Background Disorders of organic acid (OA) metabolism are generally detected by qualitative analysis of urine organic acids by gas chromatography/mass spectrometry (GC/MS) which was well established in developed countries since 1980s. Confirmation of the diagnosis of organic acid disorders by OA analysis, enzyme analysis and molecular study is a difficult task in developing countries. Methods During 2001–2004, we had analysed 442 urine samples in 365 patients and identified 12 cases of organic acid disorders. Results We identified the following disorders: alkaptonuria (ALK) = 1, isovaleric acidemia (IVA) = 3, propionic acidemia (PA) = 2, methylmalonic acidemia (MMA) = 3, glutaric aciduria, type I (GA-I) = 1, multiple carboxylase deficiency (MCD) = 1, and glutaric acidemia, type II (GA-II) = 1. Conclusions OA disorders had never been diagnosed in Thailand before, until GC/MS technology was introduced to Thailand in 2001. Urine OA analysis also provided a diagnostic clue to other inborn errors of metabolism including amino acid disorders, urea cycle disorders, disorders of carbohydrate metabolism, and mitochondrial fatty acid oxidation disorders. Since then, we were able to diagnose numerous disorders, which led to prompt treatment and better outcome in our patients.