• Journal of The Korean Society of Inherited Metabolic disease
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• v.4 no.1
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• pp.23-29
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• 2004

Cystinosis, an autosomal recessively inherited lysosomal storage disease, results from impaired transport of the amino acid cystine out of cellular lysosomes. The consequent accumulation and crystallization of cystine destroys tissues, causing growth retardation, Fanconi syndrome, renal failure, eye problems, and endocrinopathies. The gene for cystinosis, CTNS, was mapped to chromosome 17p13. The diagnosis of cystinosis is made by measuring the leukocyte cystine content and the presence of typical corneal crystals on slit-lamp examination is also diagnostic. Since treatment with cysteamine has proved extremely effective, early diagnosis and treatment are critical aspects. We experienced a typical case of cystinosis in a 12-year-old boy with growth retardation.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.15 no.2
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• pp.59-64
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• 2015

Purpose: Lactate has two optical isomers, L-lactate and D-lactate. In human L-lactate is the most abundant enantiomer of lactate. As plasma and urinary levels of L-lactate is associated with inherited metabolic disorders in general, D-lactate have been linked to the presence of diabetes and inflammatory bowel disease. Previously developed techniques have shown several limitations to further evaluate D-lactate as a biomarker for this condition. In this paper, we describe a highly sensitive, specific and fast liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the analysis of D-, L-lactate in urine. Methods: D- and L-lactate were quantified using high performance liquid chromatography tandem mass spectrometry (LC-MS/MS) with labelled internal standard. Samples were derivatized with (+)-O,O'-diacety-L-tartaric anhydride (DATAN) and seperated on a Poroshell 120 EC-C18 column. Results: Quantitative analysis of D-, and L-lactate was achieved successfully. Calibration curves were linear (r>0.999) over $0.5-100{\mu}g/mL$. Stabilities for samples were within the 10% varation. Inter- and Intra-day assay variations were below 10%. Conclusion: The presented method proved to be suitable for the quantitation of D- and L-lactate and opens the possibility to explore the use of D-lactate as a biomarker.

• Journal of Genetic Medicine
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• v.10 no.1
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• pp.1-6
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• 2013

Chronic granulomatous disease (CGD) is a rare inherited disorder of a defective NADPH oxidase enzyme, resulting in very low or no production of superoxide and subsequent reactive oxygen species. Consequently, patients with CGD are highly susceptible to severe bacterial and fungal infections. CGD is a genetically heterogeneous disease caused by defects in any one of the genes encoding the NADPH oxidase components. CGD generally affects about 3-4 per 1,000,000 individuals; thus, it is surprising that the prevalence of CGD on Jeju Island is 34.3 per 1,000,000 individuals. At present, 20 patients with CGD from 14 unrelated families on Jeju Island have been identified; nine males and 11 females. All patients with CGD tested on Jeju Island had an identical and homozygous mutation (c.7C>T in CYBA, p.Q3X in $p22^{phox}$). Therefore, all patients were autosomal recessive form of CGD. This strongly suggests that the unique and identical mutation in CYBA may be inherited from a common proband. Using mutation-specific primers to detect the mutated allele in CYBA, the frequency of subjects carrying a mutated allele was 1.3% of enrolled subjects from Seogwipo City. Further studies are necessary to elucidate how frequently this mutant allele occurs in the population on Jeju Island. Additionally, it is important to construct a national registry system to understand the pathophysiology of CGD and develop a strategy for long-term therapy.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.14 no.1
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• pp.48-53
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• 2014

Smith-Lemli-Opitz syndrome (SLO) is a rare, autosomal recessive disease caused by an inborn error in cholesterol synthesis. Patients with this disease suffer from multiple malformations due to reduced activity of 7-dehydrocholesterol reductase (DHCR7), which increases 7-dehydrocholesterol (7DHC) and 8-dehydrocholesterol (8DHC) concentrations and decreases cholesterol concentration in body fluids and tissue. Here, we describe Korean siblings with SLO who were diagnosed recently, and performed a review of literature about Korean cases with SLO to date. Microcephaly and syndactyly of the second and third toes are the most common physical finding in SLOS patients. Other malformations including growth failure, cleft palate or bifid uvula, various heart malformation, genital ambiguity in males are also accompanied. Not all patients showed low levels of serum cholesterol, so DHCR7 mutation analysis can be helpful to confirmative diagnosis. Two mutations on p.R352 locus (p.R352W and p.R352Q) are commonly identified in Korean SLO patients. Although rare in Korea, SLO should be considered in the differential diagnosis of growth failure with intellectual disability, especially in patients with multiple congenital anomalies.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.16 no.3
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• pp.117-122
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• 2016

제1형 고셔병(Gaucher disease type 1)은 리소좀 효소인 산성 ${\beta}$-글루코시다아제(acid ${\beta}-glucosidase$)의 결핍으로 인한 리소솜 축적 질환이다. 효소 활성도가 감소되어 기질이 축적되어, 간비종대, 빈혈, 혈소판감소증 및 골질환을 포함한 전신 증상이 발생한다. 재조합 효소 단백을 정맥 주입하는 효소 대체요법(Enzyme replacement therapy)는 지난 20년 넘게 고셔병의 표준 치료법이었다. 그러나 성공적인 효소 대체요법에도 불구하고, 심각한 폐증상과 골격 증상 등 고셔병 치료에 여전히 해결되지 않는 문제들이 남아 있다. 기질 감소 치료(Substrate reduction therapy)는 기질의 생합성을 억제하여 축적을 감소시킨다. 최근 새로운 경구용 기질감소 치료제인 엘리글루스타트(eliglustat)가 적합한 CYP2D6 대사 표현형을 가진 고셔병 성인 환자를 위한 1차 치료제로 미국과 유럽에서 승인되었다. 엘리글루스타트가 아직 한국에서는 쓰이지 않고 있지만, 본 종설에서는 문헌 검토를 통해 고셔병의 새로운 치료로서의 효소 대체요법을 소개하고자 한다. 아직 확고한 결론을 도출하기에는 연구 결과가 제한적이기는 하지만, 현재까지의 데이터에 따르면 엘리글루스타트는 임상 효능에 있어서 효소 보충 요법에 비열등성을 보인다. 장기 결과에 대한 추가 연구가 필요하지만, 엘리글루스타트의 승인은 해당 1형 고셔병 성인 환자들에게 경구 치료제라는 새로운 선택을 가능하게 하였다. 향후 국내에서 엘리글루스타트가 처방 가능해 지면, 각 환자 마다 철저한 평가를 통해 치료법을 선택할 수 있도록 해야 할 것이다. 나아가, 국내 1형 고셔병 환자들을 위해 엘리글루스타트의 사용에 관한 임상적 지침 또한 조만간 개발될 필요가 있다.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.16 no.2
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• pp.62-69
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• 2016

Newborn screening of some urea cycle disorders has little benefits because of early severe symptoms before the result, low sensitivity (especially hypocitrullinemia) and poor prognosis. But in case of citrullinemia, citrin deficiency and argininosuccinic aciduria diagnosed as elevated citrulline, newborn screening is helpful for early diagnosis and treatment before the symptom. Distinction between the clinical forms of these diseases is based on clinical findings and biochemical results, however, they may not be clearcut. Treatment is different from each other, so exact diagnosis is essential. Here, the diagnostic algorithm for elevated citrulline after tandem mass screening has been proposed. Minimizing total process time from sampling to report of the results is important in Korea for diagnosis and treatment of these disorders.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.17 no.4
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• pp.266-269
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• 2014

Gilbert syndrome is the most common inherited disorder of bilirubin glucuronidation. It is characterized by intermittent episodes of jaundice in the absence of hepatocellular disease or hemolysis. Hereditary spherocytosis is the most common inherited hemolytic anemia and is characterized by spherical, osmotically fragile erythrocytes that are selectively trapped by the spleen. The patients have variable degrees of anemia, jaundice, and splenomegaly. Hereditary spherocytosis usually leads to mild-to-moderate elevation of serum bilirubin levels. Severe hyperbilirubinemia compared with the degree of hemolysis should be lead to suspicion of additional clinical conditions such as Gilbert syndrome or thalassemia. We present the case of a 12-year-old boy with extreme jaundice and nausea. The diagnosis of hereditary spherocytosis was confirmed by osmotic fragility test results and that of Gilbert syndrome by genetic analysis findings.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.1 no.1
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• pp.5-12
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• 2001

아시아 및 한국에서 처음 발견된 3명의 소아 Ethylmalonic encephalopathy (EE) 환자들은 riboflavin을 이용한 치료법에 점진적인 호전을 보인 것으로 나타났다. Ethylmalonic aciduria가 3가지 효소-2-methyl-branched-chain acyl CoA dehydrogenase (2MBCAD), iso-valeryl CoA dehydrogenase (IVCAD), 그리고 short-chain acyl CoA dehydrogenase (SCAD) - 들의 부분적인 결함으로 생긴다는 가설하에 dehydrogenase (탈수효소)의 보조 효소인 riboflavin이 부분적으로 나마 치료 과정에서 어떤 역할을 수행하는지의 여부를 살펴보았다. 다음의 세 증례에서 riboflavin 혹은 coenzyme Q10을 병행하여 치료한 결과 인지 행동(cognitive behavior)과 만성 점액성 설사(chronic mucoid diarrhea)가 호전된 것으로 관찰되었다. 또한, 치료 후 운동 기능도 일부 호전되었다. EE의 질병 발생 기전이 현재까지 완전히 밝혀지지는 않았지만, 세 명의 EE 환자들의 치료경과를 관찰하여 위의 가설을 뒷받침 할 수 있었다.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.6 no.1
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• pp.6-14
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• 2006

Propionic acidemia is an autosomal recessive metabolic disorder caused by a defect of propionyl CoA carboxylase with resultant accumulation of toxic organic acid metabolites. This disorder is biochemically characterized by metabolic acidosis, ketoacidosis, hyperglycinemia and hyperammonemia. Clinical symptoms are very heterogeneous and present as a severe neonatal-onset or a late-onet form. We describe one case of propionic acidemia in a 4-year-old boy who has developed gait disturbance after acute metabolic decompensation.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.11 no.1
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• pp.103-105
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• 2011

고호모시스틴혈증(hyperhomocysteinemia)은 호모시스테인과 메티오닌의 대사과정에 관여하는 여러 효소들의 결핍에 의해 발생할 수 있으며, 대표적인 효소 결핍으로는 cysthathione beta-synthase (CBS) 결핍증, Methionine synthase (MS) 결핍증, methylenetetrahydrofolate reductase (MTHFR) 결핍증이 있다. 이들은 고호모시스테인혈증을 보이나 임상증상, 메티오닌의 동반 상승, 거대적아구성빈혈, 메칠말로닌산뇨증등의 동반 여부등을 토대로 감별진단에 도움을 받을 수 있다. 본 연자는 뇌혈전증과 뇌졸중을 동반하는 고호모시스테인혈증의 원인으로 MTHFR 유전자의 돌연변이를 발견한 증례를 경험하였기에 이를 보고하는 바이다.