Quantification of Organic Acids in Amniotic Fluid for Prenatal Diagnosis of Organic Acidemia / 소아과

PURPOSE: Since 1997, the quantification of organic acids in urine has become possible in Korea. This helped to diagnose a great variety of inborn errors of metabolism. However, we still don't know the normal value of organic acids in amniotic fluid, therefore it is impossible for doctors to make a correct diagnosis of inborn errors of metabolism in prenatal care. We tried to confirm the normal value of organic acid in amniotic fluid. METHODS: From Jan. 1998 to Dec. 2001, we carried out amniocentesis and were able to obtain 43 samples of amniotic fluid from between 16 and 20 weeks of gestation, and quantified 82 organic acids to come up with a normal value. Organic acid concentrations were quantified with gas chromatography, and the individual acids were identified with mass spectrometry. To isolate organic acids from amniotic fluid, we used a solvent extraction method with ethylacetate. Derivatization was done with MSTFA(N-methy-N-trimethylsilylfluoroacetamide). RESULTS: The results of this study showed that when organic acid concentrations in amniotic fluid were compared with those in urine, TCA cycle intermediates(lactate, pyruvate, malate, 2-ketoglutarate, citrate etc) and ketone body(3-hydroxybutyric acid, acetoacetate etc) were found at significantly higher levels. CONCLUSION: Because TCA cycle intermediate in amniotic fluid is found at high concentrations, we could expect that diagnosis of mitochondria disorder is difficult. Organic acids other than TCA cycle intermediates were undetectable in amniotic fluid. Therefore, prenatal diagnosis of organic acidemias is possible. In our study, the prenatal diagnosis of methylmalonic acidemia could be made by using the measurement of methylmalonic acid in the amniotic fluid taken at high risk pregnancy with a family history of methylmalonic acidemia.

The Effect and Factors Affecting on Lipid Status of Valproate Therapy in Children with Epilepsy / 대한소아신경학회지

PURPOSE: Antiepileptic drugs may alter serum lipid status in epileptic patients. We conducted this study to assess the effect of valproate on serum levels of total cholesterol(TC), triglycerides(TG), low-density lipoprotein(LDL), high-density lipoprotein(HDL), and TC/HDL ratio, and to investigate the factors affecting serum lipid status in children with epilepsy who had been receiving valproate therapy. METHODS: Thirty epileptic children(16 males, 14 females, mean age 7.4+/-3.3 years) were evaluated for serum lipid status at the onset and the 6, 12 and 24 months of valproate therapy, and were analysed changes and potential factors of affecting changes such as sex, body mass index, valproate concentration, in serum lipid levels during valproate therapy. RESULTS: TC were significantly lowered during first 12 months of valproate theraphy (P<0.05). LDL were lowered during first 12 months. HDL and TC/HDL ratio were not changed and TG were increased during valproate theraphy but not reach to statistical significance. TC, TG, LDL, and HDL return to pretreatment levels after 24 months of valproate theraphy. TC, LDL, HDL, and TC/HDL ratio changes were not significantly different by sex and initial body mass index, but TG were significantly increased in group of BMI below 20(P<0.05). LDL levels were significantly decreased correlation to serum valproate concentration(r=-0.2915. P<0.05). CONCLUSION: Our results suggest that valproate therapy would not increase a risk for atherosclerotic disorders in adulthood, but weight gain with a metabolic consequence of obesity would increase risk for atherosclerotic disorders in adulthood.

The Clinical Analysis of Children Who Increase Urine gamma-hydroxybutyric Acid with Seizure Disorder / 대한소아신경학회지

PURPOSE: This study was performed to analyse urine gamma-hydroxybutyric acid(GHB) in children with seizures, and to investigate the pattern of seizures and neurologic abnormalities in children related with gamma-hydroxybutyric aciduria. METHODS: We reviewed retrospectively medical records of children who admitted to our hospital with seizures between August 1. 2001 and February 28. 2003. We compared urine GHB levels with controls, and also analyzed the clinical features of patients who showed increased urine GHB. RESULTS: The mean urine GHB was 1.7+/-1.6 mmol/mol cr in febrile seizures, 1.8+/-2.5 mmol/mol cr in non-febrile seizures, and 1.8+/-2.0 mmol/mol cr in controls. Compared with control group, there was no significant difference in urine GHB levels(P>0.05). In 8 of 64 children with seizures, GHB levels increased above 2 standard deviation of normal controls. The types of seizure in children who showed increased urine GHB were generalized tonic clonic seizure in 3 patients, complex partial seizure in 2 patients, febrile seizure in 2 patients, and benign Rolandic epilepsy in 1 patient. 3 patients showed neurologic abnormalities, 4 patients showed electroencephalographic abnormalities, and 2 patients of 6 patients who performed brain imaging study showed brain imaging abnormalities. CONCLUSION: Children with gamma-hydroxybutyric aciduria should be suspected succinic semialdehyde dehydrogenase deficiency as a cause of underlying disease.