• Journal of The Korean Society of Inherited Metabolic disease
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• v.14 no.1
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• pp.10-18
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• 2014

Recent advances in the diagnosis and treatment of inborn errors of metabolism have improved substantially the prognosis of many of these diseases, if diagnosed early enough before irreversible damage occurs. This makes it essential that the practicing pediatrician, especially neonatologists be familliar with the clinical presentations and systematic approaches of these disorders. Characteristic clinical presentations, methods of systematic approach and typing of various disorders is discussed in this review. The signs of neurological dysfunctions of many IEMs manifesting in the neonatal period is very nonspecific, such as poor feeding, poor sucking, apnea or tachypnea, vomiting, hypertonia, hypotonia, seizure, letharginess, consciousness change and coma. Many other non-metabolic severe disorders of neonatal period such as neonatal sepsis and intracerebral hemorrhage share these nonspecific symptoms. Hyperammonemia, metabolic acidosis, ketosis and hyperlatic acidemia are observed in many of these conditions but there are exceptions in which conditions all basal laboratory tests are normal, such as NKH, sulfite oxidase deficiency and peroxisomal disorders. According to the results of basal laboratory tests, IEMs in the neonatal period can be categorized in to 6 types. Grouping of IEMs into 6 types will make confirmatory tests and early emergency treatment more efficient.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.5 no.1
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• pp.76-87
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• 2005

Various disorders cause hyperammonemia during childhood. Amongthem are those caused by inherited defects in urea synthesis and related metabolic pathways. These disorders can be grouped into two types: disorders of the enzymes that comprise the urea cycle, and disorders of the transporters or metabolites of theamino acids related to the urea cycle. Principal clinical features of these disorders are caused by elevated levels of blood ammonium. Additional disease-specific symptoms are related to the particular metabolic defect. These specific clinical manifestations are often due to an excess or lack of specific amino acids. Treatment of urea cycle disorders and related metabolic diseases consists of nutritional restriction of proteins, administration of specific amino acids, and use of alternative pathways for discarding excess nitrogen. Although combinations of these treatments are extensively employed, the prognosis of severe cases remains unsatisfactory. Liver transplantation is one alternative for which a better prognosis is reported.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.23 no.2
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• pp.1-7
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• 2023

Inherited metabolic disorders (IMD) are a group of disorders involving various metabolic pathways. Genetic diagnosis of IMD has been challenging because of extremely heterogeneous nature and extensive laboratory and/or phenotype overlap. Conventional genetic diagnosis was a gene-by-gene approach that needs a priori information on the causative genes that might underlie the IMD. Recent implementation of next-generation sequencing (NGS) technologies has changed the process of genetic diagnosis from a gene-by-gene approach to simultaneous analysis of targeted genes possibly associated with the IMD using gene panels or using whole exome/genome sequencing (WES/WGS) covering entire human genes. Clinical NGS tests can be a cost-effective approach for the rapid diagnosis of IMD with genetic heterogeneity and are becoming standard diagnostic procedures.

• The Journal of the Korean life insurance medical association
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• v.18
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• pp.107-110
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• 1999

The disorders of congenital metabolic errors causing mental retardation can be prevented by early diagnosis and treatment. We analysed 144,000 neonatal blood samples for phenyketonuria(PKU), maple syrup urine disease(MSUD), homocystinuria(HCU) and histidinuria(HE) by bacterial inhibition method, and galactosemia(GAL) by Paigen method. In our survey, the positive were 4 samples in PKU(4mg/dl;2, 6mg/dl;1, 8mg/dl;1), 8 samples in MSUD(4mg/dl;2, 6mg/dl;2, 8mg/dl;3, 10mg/dl;1), 4 samples in HCU(4mg/dl;2, 6mg/dl;2), 4 samples in Galactosemia(4mg/dl;2, 6mg/dl;1, 8mg/dl;1), respectively. while, no one was positive in HE. The frequncy rate were 1/36,000 for PKU, HCU and GAL, 1/18,000 for MSUD, respectively. But those for HE couldn't be detected in our survey. In this study, the hightest frequency rate was 1/18,000 of MSUD, following were 1/36,000 for PKU, HCU and GAL, respectively. As results our data, it is our opinion that neonatal screening should be performed in terms of national policies for ealy diagnosis and theraphy.

• Clinical and Experimental Pediatrics
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• v.54 no.10
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• pp.425-428
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• 2011

Ornithine transcarbamylase (OTC) deficiency is well known as the most common inherited disorder of the urea cycle, and 1 of the most common causes of hyperammonemia in newborns. We experienced a case of a 3-day-old boy with OTC deficiency who appeared healthy in the first 2 days of life but developed lethargy and seizure soon afterwards. His serum ammonia level was measured as > $1,700{\mu}g/dL$ (range, 0 to $45{\mu}g/dL$). Continuous renal replacement therapy (CRRT) in the mode of continuous venovenous hemodiafiltration was immediately applied to correct the raised ammonia level. No seizure occurred after the elevated ammonia level was reduced. Therefore, CRRT should be included as 1 of the treatment modalities for newborns with inborn errors of metabolism, especially hyperammonemia. Here, we report 1 case of successful treatment of hyperammonemia by CRRT in a neonate with OTC deficiency.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.14 no.2
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• pp.174-177
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• 2014

Isolated methylmalonic acidemia (MMA) is a group of autosomal recessive inborn errors of metabolism caused by impaired activity of methylmalonyl-coenzyme A mutase (MCM). Mutations in the gene encoding MCM (MUT ) is the most common cause of isolated MMA. In this report, we identify an asymptomatic 15 days old female who had elevated C3-acylcarnitine (C3) in the newborn screening. Her serum homocysteine was normal and urine methylmalonic acid was increased that suggested isolated MMA. She was maintained on a low-protein diet and carnitine supplementation. At 3 months of age, she was still asymptomatic and had normal growth. We analyzed MUT gene mutations. Two heterozygote mutations in the MUT gene were identified including c.323G>A and c.1672+2T>C (IVS8(+2)T>C. Among these, c.1672+2T>C (IVS8(+2)T>C) have not been described previously.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.12 no.2
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• pp.94-98
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• 2012

Purpose: Developmental delay and mental retardation are frequently occurring disorders that present major socio-economic burden on the affected individual's family and society. Both can be congenital or acquired. However, a large number of people are institutionalized without exact diagnosis and, as a result, have not received proper care. Methods: 508 subjects with mental retardation or developmental delay from six institutions in Chung Buk Province were clinically evaluated and screened for metabolic and endocrinologic problems between 2000 and 2012. Results: Clinical genetic disorders were observed in 52 (10.2%) subjects. Cerebral palsy attributed to 21% of the institutionalized. 18 (3.5%) were diagnosed with metabolic disorders and 13 (2.6%) exhibited secondary endocrinologic dysfunction. Over 16% showed metabolic evidence of malnutrition. Conclusion: 21% and 3.5% of the population institutionalized due to mental retardation or developmental delay were afflicted by preventable cerebral palsy and metabolic disorders, respectively. Through early identification of the causes and early treatment, it may be possible to prevent, reduce, or alleviate the disability of many institutionalized individuals. Further research is imperative for establishing guidelines for diagnostic investigation for mental retardation.

• Journal of Korean Medical Science
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• v.33 no.51
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• pp.324.1-324.6
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• 2018

Oxysterol $7{\alpha}$-hydroxylase deficiency is a very rare liver disease categorized as inborn errors of bile acid synthesis, caused by CYP7B1 mutations. As it may cause rapid progression to end-stage liver disease even in early infancy, a high index of suspicion is required to prevent fatal outcomes. We describe the case of a 3-month-old boy with progressive cholestatic hepatitis and severe hepatic fibrosis. After excluding other etiologies for his early liver failure, we found that he had profuse urinary excretion of $3{\beta}$-monohydroxy-${\Delta}^5$-bile acid derivatives by gas chromatography/mass spectrometry analysis with dried urine spots on filter paper. He was confirmed to have a compound heterozygous mutation (p.Arg388Ter and p.Tyr469IlefsX5) of the CYP7B1 gene. After undergoing liver transplantation (LT) from his mother at 4 months of age, his deteriorated liver function completely normalized, and he had normal growth and development until the current follow-up at 33 months of age. We report the first Korean case of oxysterol $7{\alpha}$-hydroxylase deficiency in the youngest infant reported to undergo successful living donor LT to date.

• Clinical and Experimental Pediatrics
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• v.48 no.4
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• pp.369-375
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• 2005

Purpose : Many inborn errors of metabolism can be completely cured with early detection and early treatment. This is why neonatal screening on inborn errors of metabolism is implemented worldwide. In this study, a cost-benefit analysis was performed on the neonatal screening of phenylketonuria and congenital hypothyroidism in Korea. Methods : This study included 2,908,231 neonates who took the neonatal screening on phenylketonuria and congenital hypothyroidism in Korea from January 1991 to December 2003. From those neonates, the incidence rates of phenylketonuria and congenital hypothyroidism were measured. Furthermore, based on 495,000 babies born in 2002, were calculated and compared the total costs in case when neonatal screening on phenylketonuria and congenital hypothyroidism is implemented, and when not. Results : If the neonatal screening on phenylketonuria and congenital hypothyroidism is implemented, benefits far exceed costs at a ratio of 1.77 : 1 in phenylketonuria, and 11.11 : 1 in congenital hypothyroidism. In terms of wons, the present neonatal screening on phenylketonuria and congenital hypothyroidism will gain us more than 29 billion wons every year. Conclusion : This study only concerns the monetary aspects of the neonatal screening. Therefore, the benefits of the neonatal screening is underestimated by ignoring precious but not measurable values such as quality of life. However, the present neonatal screening on phenylketonuria and congenital hypothyroidism is found to be beneficial and should continue for the good of the nation as well as that of the patients.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.18 no.2
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• pp.35-42
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• 2018

Purpose: To follow up Korean patients with metabolic and endocrine disorders ascertained by Korea Genetics Research Center, and assess the long-term effectiveness of extended newborn screening program in Korea. Methods: From January 2000 to December 2017, tandem mass spectrometry and fluoroimmunoassay were employed in extended newborn screening (NBS). The NBS program obtained dried blood spots from 283,626 babies, 48 hours after birth, and screened for galactosemia, congenital hypothyroidism (CH), congenital adrenal hyperplasia (CAH), and 50 preventable inborn errors of amino acid, fatty acid, and organic acid metabolism. Results: 28 cases of amino acid disorders, 75 cases of organic acid disorders, 27 cases of fatty acid disorders, 51 cases of urea cycle disorders, 127 cases of CH, 14 cases of CAH, and 15 cases of galactosemia were ascertained through NBS and subsequent confirmatory laboratory tests. Patients with amino acid metabolic disorders, galactosemia, CH, or CAH were more likely to have a better long-term outcome if detected early. Early management of MSUD led to much better outcome in over 90%. Despite early intervention, 32% of other organic acidemia cases still resulted in developmental delay and neurological problems. Fatty acid disorders showed varied results; those with EMA and MCAD had a good outcome, but those with VLCAD had serious neurological problems and considerably higher mortality. 75% with UCD experienced serious neurological complications and higher mortality. Conclusion: The nation-wide NBS program must be accompanied by comprehensive long-term management and physician and family education of inborn errors of metabolism for a better outcome.