• Journal of The Korean Society of Inherited Metabolic disease
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• v.23 no.1
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• pp.1-11
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• 2023

Inborn errors of metabolism encompass a wide variety of disorders, frequently affecting bone. This review presents a comprehensive retrospect on the primary involvement of bone in inborn errors of metabolism. Primary involvement of bone in inborn errors of metabolism includes entities that primarily affect the bone marrow, mineral component or cartilage. These include lysosomal storage disorders, hypophosphatasia, and hereditary hypophosphatemic rickets. In this review, we discuss the primary involvement of bone in inborn errors of metabolism (hypophosphatasia, X-linked hypophosphatemic rickets, Gaucher disease, and mucopolysaccharidoses) along with the therapeutic agents used in clinical settings, diagnostic strategies, and general management. With the development of disease-specific targeted therapies and supportive care, more number of patients with these disorders live longer and survive into adulthood. Moreover, skeletal symptoms have become a more prominent feature of these disorders. This makes the awareness of these skeletal symptoms more important.

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.689-698
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• 2013

The production and characterization of an active recombinant N-acetylgalactosamine-6-sulfate sulfatase (GALNS) in Escherichia coli BL21(DE3) has been previously reported. In this study, the effect of the signal peptide (SP), inducer concentration, process scale, and operational mode (batch and semi-continuous) on GALNS production were evaluated. When native SP was presented, higher enzyme activity levels were observed in both soluble and inclusion bodies fractions, and its removal had a significant impact on enzyme activation. At shake scale, the optimal IPTG concentrations were 0.5 and 1.5 mM for the strains with and without SP, respectively, whereas at bench scale, the highest enzyme activities were observed with 1.5 mM IPTG for both strains. Noteworthy, enzyme activity in the culture media was only detected when SP was presented and the culture was carried out under semi-continuous mode. We showed for the first time that the mechanism that in prokaryotes recognizes the SP to mediate sulfatase activation can also recognize a eukaryotic SP, favoring the activation of the enzyme, and could also favor the secretion of the recombinant protein. These results offer significant information for scaling-up the production of human sulfatases in E. coli.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.22 no.2
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• pp.46-52
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• 2022

Inborn errors of metabolism (IEM) are very rare and genetically transmitted diseases and have man y different symptoms related with multisystemic involvement. More rarely, endocrinopathies can be an early and first symptom of IEM, but presents with signs of later complications in adolescent or adulthood. The mechanisms of endocrine dysfunction in IEM are poorly understood. Hypogonadotropic hypogonadism is common in hemochromatosis, adrenoleukodystrophy, galactosemia, and glycogen storage disease. Many girls with classic galactosemia are at high risk for premature ovarian insufficiency (POI), despite an early diagnosis and good control. Mitochondrial diseases are multisystem disorders and are characterized by hypo- and hypergonadotrophic hypogonadism, thyroid dysfunction and insulin dysregulation. Glycogen storage disorders (GSDs), especially type Ia, Ib, III, V are assocciated with frequent hypoglycemic events. IEM is a growing field and is not yet well recognized despite its consequences for growth, bone metabolism and fertility. For this reason, clinicians should be aware of these diagnoses and potential endocrine dysfunction.

• Clinical and Experimental Pediatrics
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• v.62 no.2
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• pp.43-47
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• 2019

Hyperammonemia can be caused by several genetic inborn errors of metabolism including urea cycle defects, organic acidemias, fatty acid oxidation defects, and certain disorders of amino acid metabolism. High levels of ammonia are extremely neurotoxic, leading to astrocyte swelling, brain edema, coma, severe disability, and even death. Thus, emergency treatment for hyperammonemia must be initiated before a precise diagnosis is established. In neonates with hyperammonemia caused by an inborn error of metabolism, a few studies have suggested that peritoneal dialysis, intermittent hemodialysis, and continuous renal replacement therapy (RRT) are effective modalities for decreasing the plasma level of ammonia. In this review, we discuss the current literature related to the use of RRT for treating neonates with hyperammonemia caused by an inborn error of metabolism, including optimal prescriptions, prognosis, and outcomes. We also review the literature on new technologies and instrumentation for RRT in neonates.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.21 no.1
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• pp.1-6
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• 2021

Among the various etiologies of cardiomyopathy, inborn errors of metabolism (IEM) is one of the underlying causes, especially in the pediatric population. The accurate identification of the IEM of cardiomyopathy may lead to better prognosis through disease-specific management. Therefore, clinicians should always keep in mind the possibility that IEM may be one of the underlying etiologies of cardiomyopathy, and carry out multi-systematic clinical approach to diagnosis of IEM. This review covers the pathophysiology, clinical presentations, typical laboratory findings, diagnosis, and proper treatment of each type of IEM-induced cardiomyopathy in pediatric patients to gain a deeper understanding of this subject.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.24 no.6
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• pp.518-527
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• 2021

Purpose: The incidence of hepatic steatosis among children has been increasing; however, data distinguishing simple steatosis from a more complex disorder are lacking. Methods: This study identified the etiologies resulting in hepatic steatosis through a retrospective review of pediatric liver biopsies performed in the last 10 years. A total of 158 patients with hepatic steatosis proven by histopathological evaluation were enrolled in the study, and baseline demographic features, anthropometric measurements, physical examination findings, laboratory data, ultrasonographic findings, and liver histopathologies were noted. Results: The two most common diagnoses were inborn errors of metabolism (IEM) (52.5%) and nonalcoholic fatty liver disease/steatohepatitis (NAFLD/NASH) (29.7%). The three most common diseases in the IEM group were glycogen storage disorders, Wilson's disease, and mitochondrial disease. The rates of consanguineous marriage (75.6%; odds ratio [OR], 26.040) and positive family history (26.5%; OR, 8.115) were significantly higher (p=0.002, p<0.001, respectively) in the IEM group than those in the NAFLD/NASH group. Younger age (p=0.001), normal anthropometric measurements (p=0.03), increased aspartate aminotransferase levels (p<0.001), triglyceride levels (p=0.001), and cholestatic biochemical parameters with disrupted liver function tests, as well as severe liver destruction of hepatic architecture, cholestasis, fibrosis, and nodule formation, were also common in the IEM group. Conclusion: Parents with consanguinity and positive family history, together with clinical and biochemical findings, may provide a high index of suspicion for IEM to distinguish primary steatosis from the consequence of a more complex disorder.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.14 no.1
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• pp.19-28
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• 2014

• Journal of The Korean Society of Inherited Metabolic disease
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• v.14 no.2
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• pp.123-134
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• 2014

Recent advances in the diagnosis and treatment of inborn errors of metabolism (IEM) have improved substantially the prognosis of many of these diseases, if diagnosed early enough before irreversible damage occurs. Diseases of inborn errors of metabolism are so diverse over several hundred disease up to now and may be several thousand in near future, and these diversities of IEMs make clinicians embarassed. 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. But after neonatal period, the signs of neurological deficits become specific and localized. The results of routine basal laboratory tests such as metabolic acidosis, hyperammonemia, lactic acidemia, ketonemia or hyperuricemia can give very important clinical clues for the diagnosis of IEMs. Even no abnormal findings on routine laboratory test could be very important clue for NKH, sulfite oxidase deficiency and peroxisomal disorders. These various clinical manifestations of these diverse diseases can be categorized and summarized. This makes it essential that the practicing clinicians be familiar with the clinical presentations and symptomatic and systematic approaches of these disorders. Characteristic clinical presentations, methods of symptomatic and systematic approach and typing of various disorders is discussed in this review.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.6 no.1
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• pp.24-31
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• 2006

Purpose : The Ministry of Health and Social Affairs adopted newborn screening for the low-income families in 1991 and expanded in 1997 to cover all newborns. At the beginning of the program 6 diseases were selected for screening but the number of screening items had been reduced to two (congenital hypothyroidism and phenylketonuria) from the year 1995. Now, the government program has a fifteen year history. The purpose of this study was to analyze results of neonatal screening tests and prevalence at birth of phenylketonuria and congenital hypothyroidism in Korea. Methods : The results of neonatal screening tests were collected from public health centers during 15 years from 1991 to 2005. These data were analyzed for number of tested newborns and prevalence at birth of the inborn errors of metabolism. Results : Neonatal screening test for inborn error of metabolism was performed for 3,707,773 newborns for 15 years. Among newborns who were screened 718 congenital hypothyroidisms and 86 phenylketonurias were detected, and these presented an prevalence at bith of congenital hypothyroidism 1/5,164 and that of phenylketonuria 1/43,114. The total prevalence of two diseases was 1/4,612. Conclusion : National screening program should be expanded to include all items of screening tests for whole newborns and established correct prevalence of other inherited metabolic diseases in Korea.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.21 no.3
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• pp.155-162
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• 2018

Infant formula is classified into standard cow's milk-based and special formulas. This review aimed at summarizing the types of special milk formulas currently sold in Korea, and the appropriate indications for the use of these formulas; lactose free formula, soy-based formula, protein hydrolysate formula, amino acid-based formula, preterm formula, medium chain triglyceride formula, low-phosphorus formula, protein-energy-enriched formula, and formulas for inborn errors of metabolism.