Retrospective Study of Patients with Suspected Inborn Errors of Metabolism at Siriraj Hospital, Bangkok, Thailand (1997-2001)
Pornswan Wasant, MD*, Nithiwat Vatanavicharn, MD*, Chantragan Srisomsap, **, Phannee Sawangareetrakul, **, Somporn Liammongkolkul, MD*, Jisnuson Svasti, PhD***
Affiliation : * Department of Pediatrics, Faculty of Medicine, Siriraj Hospital, Mahidol University ** Laboratory of Biochemistry, Chulabhorn Research Institute, Mahidol University *** Department of Biochemistry, Faculty of Science, Mahidol University
Introduction: This retrospective clinical study was carried out on patients with suspected inborn errors of
metabolism (IEM) at Siriraj Hospital during 1997-2001. The authors investigated 114 patients by quantitative
plasma amino acid analysis.
Objective : The objective of this study was to collect and analyze epidemiologic and specific clinical data of
IEM, especially in small-molecule diseases.
Materials and Methods : All patients were categorized into 2 major groups: 1) positive diagnoses for IEM
2) negative diagnoses for IEM. The two groups were investigated, studied including statistical analysis.
Results : The authors found that most IEM ascertained through plasma amino acid analysis were small-
molecule diseases (74.3%) and amino acid disorders consisted of the most frequent disorders. The presented
data demonstrated that the ratio of positive diagnoses to all patients studied was 1:8. Epidemiological data
showed there were more male than female patients. Onset of diseases occurred predominantly during the
first month of age, and was rarely found after 3 years of age. There were histories of consanguinity in half of
the IEM patients. The most common presenting symptom was acute metabolic encephalopathy and specific
signs for small-molecule disorders included hepatomegaly, unusual urine odor, acidosis, hyperammonemia,
alteration of consciousness, and ketosis/ketonuria. These signs or symptoms indicated further metabolic
investigations.
Conclusion : Comparison of the data from Thailand with other countries showed both similarities
and differences to the Caucasian population. Thus, further studies in IEM are much needed for the Thai
population.
Keywords : Inborn errors of metabolism, Small-molecule diseases, Amino acid disorders, Consanguinity
