Research Abstract |
Importance of the neonatal mass screening for organic acidemias has been recognized worldwide. We performed basic studies to simplify, speed up and raise the sensitivity of GC/MS analysis for the screening. The results were as follows : 1) Establishment of an automated GC/MS data system : A personal computer-assisted system for automated metabolic profiling of GC/MS data and detection of disoorders was completed. 2) GC/MS screening using urine filter paper : Dried urine filter paper is convenient for sample transport. We investigated the practicality of the urine filter paper. Most of 25 compounds tested were stable on the filter paper for at least 28 days. We analyzed over 600 samples of urine filter paper samples sent from Asian countries, and detected 41 organic acidemia patients. 3) A pilot study of neonatal mass screening using GC/MS in the Shimane area : We perfromed a pilot neonatal mass screening for 4005 babies born in the Shimane area for 3 years. Among them, a baby with hyperphenylalaninemia was found, and transient neonatal abnoprmality was detected in 4.6% of babies screened. 4) Study of t-butyldimethylsilyl (TBDMS)-derivatization in organic acidemia screening using GC/MS : We studied TBDMS-derivatization method for GC/MS analysis and compared with trimethylsilyl (TMS)-derivatization, a most popularmethod. The TBDMS method was more sensitive and reliable. 5) Study of free fatty acids in dried blood filter paper : We established a simplified, sensitive method for analysis of free fatty acids in dried blood filter paper. We confirmed that 11 cases of fatty acid beta-oxidation disorders coud be identified by this method. 6) Simplified screening method for detection of fructose-1, 6-diphosphatase (FDPase) deficiency : We established arapid, simplified, non-invasive and sensitive method to detect FDPase deficiency, using only a small amount of urine. It will be useful in prevention of sudeden death because of hypoglycemia in FDPase deficiency.
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