Inherited metabolic disorders in Thailand - Siriraj experience

Abstract

The incidence of inborn erros 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 nationwide. These 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 realixed. With the exception of thalassemias, IEM 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 deficiency (OTC), argininosuccinic lyase deficiency (ALD), argininosuccinic acid synthetase deficiency (ASD); glycogen storage disorders eg Pompe's disease, Von Gierke's; organic acid disorders eg isovaleric acidemia, methylmalonic acidemia. Lysosomal storage disorders identified were GMI gangliosidosis, mucolipidosis II. Hurler, Hunter, Maroteaux-Lamy, Sialidosis (neuraminidase deficiency), Sly, Scheie, Gaucher, Niemann-Pick, Sandhoff and many other neurodegenerative disorders eg neuronal ceroid lipofuscinosis (NCL). leucodystrophies etc. Peroxisomal disorders identified were rhizomelic chondrodysplasia punctata (RCDP) and Zcllweger. Recently fatty acid oxidation disorders: MCAD. translocase deficiency and multiple carboxylase deficiency (biotinidase deficiency) were also identified.