1.Molecular Biological Advances in Human Copper Metabolism: Molecular Genetics in Wilson's Disease.
The Korean Journal of Hepatology 1998;4(3):223-234
No abstract available.
Copper*
;
Hepatolenticular Degeneration*
;
Humans*
;
Metabolism*
;
Molecular Biology*
2.Metabolic evaluation of children with global developmental delay.
Korean Journal of Pediatrics 2015;58(4):117-122
Global developmental delay (GDD) is a relatively common early-onset chronic neurological condition, which may have prenatal, perinatal, postnatal, or undetermined causes. Family history, physical and neurological examinations, and detailed history of environmental risk factors might suggest a specific disease. However, diagnostic laboratory tests, brain imaging, and other evidence-based evaluations are necessary in most cases to elucidate the causes. Diagnosis of GDD has recently improved because of remarkable advances in genetic technology, but this is an exhaustive and expensive evaluation that may not lead to therapeutic benefits in the majority of GDD patients. Inborn metabolic errors are one of the main targets for the treatment of GDD, although only a small proportion of GDD patients have this type of error. Nevertheless, diagnosis is often challenging because the phenotypes of many genetic or metabolic diseases often overlap, and their clinical spectra are much broader than currently known. Appropriate and cost-effective strategies including up-to-date information for the early identification of the "treatable" causes of GDD are needed for the development of well-timed therapeutic applications with the potential to improve neurodevelopmental outcomes.
Child*
;
Developmental Disabilities
;
Diagnosis
;
Humans
;
Metabolic Diseases
;
Metabolism
;
Neuroimaging
;
Neurologic Examination
;
Phenotype
;
Risk Factors
3.Congenital Esophageal Atresia Associated with Tracheal Bronchus and Imperforate Anus.
Si Houn HAHN ; Keun Haeng CHO ; Young Sook HONG ; Soon Kyum KIM
Journal of the Korean Pediatric Society 1989;32(4):550-555
No abstract available.
Anus, Imperforate*
;
Bronchi*
;
Esophageal Atresia*
4.Organic Acid Analysis on Urine Sample Obtaine3d from Dried Filter Paper in Newborns: Development of Screening Method for Organic Aciduria in Neborns.
Journal of the Korean Pediatric Society 2000;43(10):1311-1317
PURPOSE: Neonatal screening for inherited metabolic disease is aimed at identifying affected infants early, thus permitting medical intervention to prevent or minimize the effect of the disease. However, organic aciduria, most of which causes severe disease and mental retardation, is not yet screened routinely because of the difficulty of tests, sample collection, and expenditure of time and financial resources. This study was designed to develop a screening method for the detection of multiple organic aciduria and neuroblastoma, using dried urine filter paper. METHODS: The standard markers used for screening of organic aciduria were placed on the filter paper and analysed with the modified organic acid analysis method. The extraction efficiency and stability of standard markers were tested for the purpose of adequacy as screening markers, and the method described herein was evaluated by analyzing filter paper samples obtained from both normal newborns and patients with known organic aciduria. RESULTS: The standard markers in the filter paper left in the room temperature over a period of 5 days were still stable without significant degradation. The level of specific organic acids obtained from known organic aciduria patients were easily detectable-enough to make the diagnosis. CONCLUSION: The filter papers soaked with urines obtained from newborns or patients with suspicious metabolic diseases are adequate for screening of organic acidurias and neuroblastoma. Sample delivery to the laboratory can be handled more easily with this method and even newborn screening could be applied in the future.
Diagnosis
;
Health Expenditures
;
Humans
;
Infant
;
Infant, Newborn*
;
Intellectual Disability
;
Mass Screening*
;
Metabolic Diseases
;
Neonatal Screening
;
Neuroblastoma
5.Effect of metal ions on the stability of metallothionein in the degradation by cellular fractions in vitro.
Si Houn HAHN ; Ook Joon YOO ; William A GAHL
Experimental & Molecular Medicine 2001;33(1):32-36
Metallothioneins (MT), small molecular weight metal binding proteins are known to play an important protective role against heavy metal toxicity, either as antioxidants or pre-oxidants. However, the mode of metabolic fate of MTs in various metal complexes is not clearly understood. This study was carried out to better understand the mode of selective turnover rate of various form of MT in complexes with different metals. The degradation of in vitro translated mouse 35S-cysteine-MT was examined in lysosomal or cytosolic fractions from mouse liver by gel electrophoresis and autoradiography. Overnight incubations of MT showed extensive proteolysis in the lysosomal fraction but not in cytosolic fractions. However, Cu2+-MT was found to be stable under the same experimental condition. In contrast, Zn did not interfere with MT degradation. These results suggest that lysosomes are chiefly responsible for MT removal and appears to be selective on the metals involved in the MT complex. In vitro, translated, radiolabeled MT provides a suitable substrate for investigating the characteristics of MT degradation.
Animal
;
Copper/*metabolism/pharmacology
;
Ions
;
Liver/drug effects/*metabolism
;
Lysosomes/metabolism
;
Metallothionein/drug effects/*metabolism
;
Mice
;
Sulfur Radioisotopes
;
Support, Non-U.S. Gov't
;
Zinc/*metabolism/pharmacology
6.HFE gene mutation, C282Y causing hereditary hemochromatosis in Caucasian is extremely rare in Korean population.
Ji Yon LEE ; Kyung Hwa YOO ; Si Houn HAHN
Journal of Korean Medical Science 2000;15(2):179-182
Hereditary hemochromatosis (HFE), which affects 1 in 400 and has an estimated carrier frequency of 1 in 10 individuals in Western population, results in multiple organ damage caused by iron deposition, and is treatable if detected early. C282Y mutation in HFE gene has been known to be responsible for the most hereditary hemochromatosis cases and 5-10% of white subjects are heterozygous for this mutation. However, the prevalence of hemochromatosis in the Asian population was reported to be very low and ethnic heterogeneity has been suspected. The aim of our study was to determine the prevalence of heterozygosity and homozygosity for the C282Y HFE gene mutations in 502 unrelated Koreans. Results revealed that none of them had the mutant gene, suggesting a significant ethnic difference when compared with Caucasians. Our study excluded underlying possibility of hereditary hemochromatosis in Korean which could mimic the findings of alcoholic liver disease with iron overload or liver cirrhosis with chronic hepatitis C.
Alleles
;
Caucasoid Race/genetics*
;
DNA Primers
;
Genetic Screening
;
Genotype
;
HLA Antigens/genetics
;
Hemochromatosis/genetics*
;
Hemochromatosis/ethnology*
;
Histocompatibility Antigens Class I/genetics
;
Human
;
Korea/epidemiology
;
Mongoloid Race/genetics*
;
Point Mutation*
;
Prevalence
7.A Case of Methylmalonic Acidemia.
Jong Hoon PARK ; Si Houn HAHN ; Kee Hwan YOO ; Kwang Chul LEE ; Chang Sung SOHN ; Pyung Hwa CHOE
Journal of the Korean Pediatric Society 1989;32(7):984-989
No abstract available.
8.Molecular biological diagnosis of Spinal Muscular atrophy.
Ki Sun LEE ; Hee Yu HWANG ; Key Hyoung LEE ; Moon Sung PARK ; Si Houn HAHN ; Chang Ho HONG
Journal of Genetic Medicine 1997;1(1):33-38
Spinal muscular atrophy(SMA) is the second most common fatal disease of childhood with autosomal dominant mode of inheritance, and in its less severe form the third most common neuromuscular disease of childhood after Duchenne muscular dystrophy. The genetic defect was found to be on the long arm of chromosome 5(5q11.2-q13.3) where many genes and microsatellite markers were missing. One of the most important genes is the Survival Motor Neuron(SMN) gene which is homozygously missing in 90% of SMA patients. Another important gene, the Neuronal Apoptosis Inhibitory Protein(NAIP) gene was found to be defective in 67% of SMA type I patients. Studies so far suggest SMA occurs when the genes on the long arm of chromosome 5 are mutated or deleted. Recently our hospital encountered 2 SMA patients of type I and II respectively. These patients both had homozygously defective SMN genes but intact NAIP genes. We are reporting these cases with bibliographic review and discussion. Korean SMA patients presumably have defects in SMN genes similar to those found in European patients, although the siginificance of NAIP genes remains to be established. SMN gene defects can be easily diagnosed using PCR and restriction enzymes, and this method could be applied towards convenient prenatal diagnosis and towards screening for family members at risk.
Apoptosis
;
Arm
;
Chromosomes, Human, Pair 5
;
Diagnosis*
;
Humans
;
Mass Screening
;
Microsatellite Repeats
;
Muscular Atrophy, Spinal*
;
Muscular Dystrophy, Duchenne
;
Neuromuscular Diseases
;
Neurons
;
Polymerase Chain Reaction
;
Prenatal Diagnosis
;
Wills
9.Correlation between Genotype and Phenotype in Korean patients with Spinal Muscular Atrophy.
Seon Young WON ; Kyong Hwa RYU ; Eun Ha LEE ; Si Houn HAHN ; Ki Soo PAI ; Sung Hwan KIM
Journal of the Korean Child Neurology Society 1999;7(1):10-20
BACKGROUND: Spinal muscular atrophy (SMA) is the second most common disease with autosomal recessive mode of inheritance in children and characterized by degeneration of anterior horn cells of the spinal cord resulting in weakness and wasting of voluntary muscles. This disease is caused by deletion of many candidate genes including SMN, p44, NAIP on chromosome 5q11.2-13.3. Although molecular characteristics of candidate genes were identified, genotype-phenotype correlation has not been clearly elucidated yet. Nevertheless, gene conversion, previously described as simply as gene deletion, appears to be very important mechanism as a molecular pathogenesis, and even makes more difficult to pursue the correlation. PURPOSE: This study was aimed to define the correlation between genotype and phenotype of SMA in Korean patients. The significance of SMN gene as well as NAIP gene, p44 gene in the progress of disease process and phenotypic correlation with gene conversion was evaluated. This study was also undertaken to determine the frequency of gene rearrangements in normal population. METHOD: Eight type I SMA patients and two type II SMA patients were studied. SMN, NAIP, and p44 gene deletion were analyzed by PCR amplification and restriction enzyme digestion with DraI, DdeI and AluI, respectively. p44 gene was also analyzed by SSCP. Gene conversion was defined by centromeric and telomeric SMN gene exon 7 to exon 8 PCR amplification followed by DdeI restiction enzyme digestion. RESULT: 1) Five of eight type I patients showed deletion of SMN, NAIP and p44 gene, while the rest of type 1 and all type II patients showed deletion of SMN gene only. 2) We examined SMN and NAIP gene deletion on 100 normal newborns, which showed the deletion of centromeric SMN gene in two newborns, the relative frequency of 2% in gene rearrangement. 3) There was one case of type I SMA showing deletion of telomeric SMN exon 7 but not SMN exon 8 suggestive of gene conversion occurred during the recombination as a molecular pathogenesis. CONCLUSION: The major deletion of SMA candidate genes, SMN, NAIP, and p44 gene appear to be involved in severe phenotype since these three candidate genes deletion were noted only in type 1 cases. However, SMN gene deletion only identified both in type 1 and type 2 explains that SMN gene may plan an major role in the pathogenesis of SMA and also suggests that other factors may be affecting the severity in spinal muscular atrophy. One patient with type I which showed the conversion of the centromeric SMN gene to the teleomeric gene strongly supports that SMN gene copy number may not be correlated with the severity in SMA. Our molecular findings suggest that phenotype is not clearly correlated with genotype. Prenatal screening should be carefully undertaken to interpretate because of high frequency of gene rearrangements in normal populations.
Anterior Horn Cells
;
Child
;
Digestion
;
Exons
;
Gene Conversion
;
Gene Deletion
;
Gene Dosage
;
Gene Rearrangement
;
Genetic Association Studies
;
Genotype*
;
Humans
;
Infant, Newborn
;
Muscle, Skeletal
;
Muscular Atrophy, Spinal*
;
Phenotype*
;
Polymerase Chain Reaction
;
Polymorphism, Single-Stranded Conformational
;
Prenatal Diagnosis
;
Recombination, Genetic
;
Spinal Cord
;
Wills
10.The Amino Acid Compositions of Formula for Children with Inherited Metabolic Disorder.
Kyung Hwa RYU ; Jong Soo KIM ; Eun Ha LEE ; Il Sun KWON ; Si Houn HAHN
Journal of the Korean Pediatric Society 2002;45(1):37-43
PURPOSE: This study aimed to determine the amino acids composition, safety and efficacy of formulas recently developed by Korean dairy companies for children with inherited metabolic disorder. METHODS: The determination of amino acids concentration was performed on eight Korean formula samples. The samples were hydrolyzed with 6N HCL or performic acid and analyzed by amino acid analyzer. RESULTS: No phenylalanine, methionine or leucine was observed in PKU-1 and PKU-2 Formulas, Methionine-Free and Leucine-Free Formula, respectively. BCAA-Free Formula was free from leucine, isoleucine, and valine and MPA Formula did not contain methionine and valine. Protein-Free formula did not include any amino acids. UCD Formula contained arginine but was free of alanine, aspartic acid, glutamic acid, glycine, histidine, proline and serine. Methionine-Free Formula contained higher amounts of cystine and tyrosine was higher in PKU-1 and 2 Formulas. The amounts of isoleucine and threonine were minimal in MPA Formula. CONCLUSION: This study confirmed that the eight special formulas, developed for the first time by a Korean dairy company for children with inherited metabolic disorder contain appropriate amino acids with proper contents. Both the total amino acid amounts and specific amino acid concentrations of the formulas were appropriate for related diseases, which could be used safely by the patients with inherited metabolic disorder. For UCD Formula that contains arginine, we suggest that arginine be removed from the formula in order to use for any urea cycle defect patients before the specific diagnosis is made.
Alanine
;
Amino Acids
;
Arginine
;
Aspartic Acid
;
Child*
;
Cystine
;
Diagnosis
;
Glutamic Acid
;
Glycine
;
Histidine
;
Humans
;
Isoleucine
;
Leucine
;
Methionine
;
Phenylalanine
;
Proline
;
Serine
;
Threonine
;
Tyrosine
;
Urea
;
Valine