Detection of inborn errors of metabolism in Thai infants via gas chromatography and mass spectrometry.

We had studied inherited metabolic disorders at the Department of Pediatrics, Siriraj Hospital Faculty of Medicine, Mahidol University since 1987 using limited resources available and collaboration with other laboratories, both in Thailand and The United States. Since April 1998, we started a collaboration with MILS and Kanazawa Medical University, the Japan, studying inborn errors of metabolism in Asian Countries using urine filter paper and a new GC/MS method. We have since successfully discovered several patients with metabolic disorders. Out of 33 (high-risk) cases we sent for biochemical diagnosis (during April-July 1998), 13 abnormal results were found which is approximately 39.4%. Inherited metabolic disorders identified were as follows: medium-chain acyl CoA dehydrogenase deficiency (MCAD), multiple carboxylase deficiency (MCD), methylmalonic acidemia (MMA), Fanconi syndrome, galactosemia and neuroblastoma.

Inherited metabolic disorders in Thailand--Siriraj experience.

The incidence of inborn errors of metabolism (IEM) in Thailand is yet unknown. However, by estimation it is generally accepted to be 1 in 5,000. From a survey in 7 medical schools from different parts of the country and a large pediatric hospital in Bangkok, we found numerous cases of IEM nationwidc. Thesc were amino acid disorders, carbohydrate disorders, urea cycle defects, peroxisomal, lysosomal storage disorders, and many others. Since Thais are quite homogeneous in their genetic make-up; it is, therefore, very likely that IEM is much more prevalent than we realized. With the exception of thalassemias, IFAM is probably very common in Thailand and other countries in the Asia-Pacific region. IEM identified were amino acid disorders eg phenylketonuria, maple syrup urine disease: urea cycle disorders eg ornithine transcarbamylase deficincy (OTC), argininosuccinic lyase deficiency (ALD), argininosuccinic acid synthetasc deficiency (ASD); glycogen storage disorders eg Pompe's discase, Von Gierkc's; organic acid disorders eg, isovaleric acidemia, methylmalonic acidemia. Lysosmal storagc disorders identified were GM1 gangliosidosis, mucolipidosis II, Hurler, Hunter, Maroteaux-Lamy, Sialidosis (neuraminidase deficicncy), Sly, Scheie, Gaucher, Niemann-Pick, Sandhoff and many other neurodegeneraative disorders identified were rhizomelic chondrodysplasia punctata (RCDP) and Zellweger. Recently fatty acid oxidation disorders: MCAD, translocase deficiency and multiple carbosxylase deficiency 9biotinidase deficiency) were also identified.