• Journal of The Korean Society of Inherited Metabolic disease
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• v.11 no.1
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• pp.27-32
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• 2011

최근 유전공학의 발달로 리소좀 축적 질환에서 효소 치료제가 개발되어 실제 치료에 사용되고 있다. 현재 효소 보충 치료가 가능한 리소좀 축적 질환에는 고셔병(Gaucher disease), 파브리병(Fabry disease), 폼페병(Pompe disease), 뮤코다당체침착병(Mucopolysaccharidosis, MPS) 1형, 2형, 6형이 있으며 비교적 안전하면서 증상 완화에도 효과적으로 보인다. 그러나 이미 진행이 된 증상에 대해서는 비가역적이므로 조기에 진단을 하여 치료를 시작하는 것이 중요하다. 효소 보충 치료의 장기간에 걸친 치료 효과에 대해서 지속적인 평가가 필요하며 무엇보다 뼈와 중추신경계에 대한 효과는 제한적이므로 이에 대한 새로운 치료법의 개발이 필요하다.

• Journal of Genetic Medicine
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• v.15 no.1
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• pp.28-33
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• 2018

Fabry disease (FD) is a rare X-linked lysosomal storage disorder caused by the deficiency of ${\alpha}$-galactosidase A. Patients with classical FD present acroparesthesia, hypohidrosis, cornea verticillata, disseminated angiokeratoma, and microalbuminuria in childhood, and develop life-threatening renal, cardiac, and cerebrovascular complications typically after the fourth decade of life. To date, more than 700 mutations responsible for FD have been identified in the human GLA gene. Herein, we report a novel GLA mutation, c.1117_1141del25 (p.Gly373Profs*10), identified in an 11-year-old Korean boy with FD presenting early cardiac and neurologic manifestation and in other affected family members. The boy had acroparesthesia, hypohidrosis, cornea verticillata, and left ventricular hypertrophy. His mother and sister also had acroparesthesia. Two males on the mother's side had similar pain and died of unknown causes. The plasma ${\alpha}$-galactosidase A activity (4.1 nmol/hr/mg protein) of the patient was markedly lower than the mean value of the controls. The plasma level of globotriaosylsphingosine was elevated in the patient and all the carriers. We concluded the novel GLA mutation c.1117_1141del25 is a pathogenic mutation for FD, probably related to the early cardiac manifestation of FD.

• Journal of Genetic Medicine
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• v.20 no.1
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• pp.6-14
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• 2023

Fabry disease (FD), a rare X-linked lysosomal storage disorder, is caused by mutations in the α-galactosidase A gene gene encoding α-galactosidase A (α-Gal A). The functional deficiency of α-Gal A results in progressive accumulation of neutral glycosphingolipids, causing multi-organ damages including cardiac, renal, cerebrovascular systems. The current treatment is comprised of enzyme replacement therapy (ERT), oral pharmacological chaperone therapy and adjunctive supportive therapy. ERT has been introduced 20 years ago, changing the outcome of FD patients with proven effectiveness. However, FD patients have many unmet needs. ERT needs a life-long intravenous therapy, inefficient bio-distribution, and generation of anti-drug antibodies. Migalastat, a pharmacological chaperone, augmenting α-Gal A enzyme activity only in patients with mutations amenable to the therapy, is now available for clinical practice. Furthermore, these therapies should be initiated before the organ damage becomes irreversible. Development of novel drugs aim at improving the clinical effectiveness and convenience of therapy. Clinical trial of next generation ERT is underway. Polyethylene glycolylated enzyme has a longer half-life and potentially reduced antigenicity, compared with standard preparations with longer dosing interval. Moss-derived enzyme has a higher affinity for mannose receptors, and seems to have more efficient access to podocytes of kidney which is relatively resistant to reach by conventional ERT. Substrate reduction therapy is currently under clinical trial. Gene therapy has now been started in several clinical trials using in vivo and ex vivo technologies. Early results are emerging. Other strategic approaches at preclinical research level are stem cell-based therapy with genome editing and systemic mRNA therapy.

• Journal of Genetic Medicine
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• v.4 no.1
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• pp.45-52
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• 2007

Purpose : A simple, rapid, and highly sensitive analytical method for Gb3 in plasma was developed without labor-ex tensive pre-treatment by electrospray ionization MS/ MS (ESI-MS/MS). Measurement of globotriaosy lceramide (Gb3, ceramide trihex oside) in plasma has clinical importance for monitoring after enzyme replacement therapy in Fabry disease patients. The disease is an X-linked lipid storage disorder that results from a deficiency of the enzyme ${\alpha}$-galactosidase A (${\alpha}$-Gal A). The lack of ${\alpha}$-Gal A causes an intracellular accumulation of glycosphingolipids, mainly Gb3. Methods : Only simple 50-fold dilution of plasma is necessary for the extraction and isolation of Gb3 in plasma. Gb3 in diluted plasma was dissolved in dioxane containing C17:0 Gb3 as an internal standard. After centrifugation it was directly injected and analyzed through guard column by in combination with multiple reaction monitoring mode of ESI-MS/MS. Results : Eight isoforms of Gb3 were completely resolved from plasma matrix. C16:0 Gb3 occupied 50% of total Gb3 as a major component in plasma. Linear relationship for Gb3 isoforms w as found in the range of 0.001-1.0 ${\mu}g$/mL. The limit of detection (S/N=3) was 0.001 ${\mu}g$/mL and limit of quantification was 0.01 ${\mu}g$/mL for C16:0 Gb3 with acceptable precision and accuracy. Correlation coefficient of calibration curves for 8 Gb3 isoforms ranged from 0.9678 to 0.9982. Conclusion : This quantitative method developed could be useful for rapid and sensitive 1st line Fabry disease screening, monitoring and/or diagnostic tool for Fabry disease.

• Journal of mucopolysaccharidosis and rare diseases
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• v.3 no.1
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• pp.14-19
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• 2017

Lysosomal storage diseases (LSDs) are a group of rare inherited metabolic disorders caused by the deficiency of specific lysosomal enzymes and subsequent accumulation of substrates. Enzyme deficiency leads to progressive intra-lysosomal accumulation of the incompletely degraded substances, which cause dysfunction and destruction of the cell and eventually multiple organ damage. Patients have a broad spectrum of clinical phenotypes which are generally not specific for some LSDs, leading to missed or delayed diagnosis. Due to the availability of treatment including enzyme replacement therapy (ERT) and hematopoietic stem cell transplantation for some LSDs, early diagnosis is important. ERT products have been approved with optimal outcomes for some LSDs in the recent decades, including Gaucher, Fabry, mucopolysaccharidosis (MPS) I, Pompe, MPS VI, MPS II, and MPS IVA diseases. ERT can stabilize the clinical condition, prevent disease progression, and improve the long-term outcome of these diseases, especially if started prior to irreversible organ damage. Based on the availability of therapy and suitable screening methods in the recent years, some LSDs, including Pompe, Fabry, Gaucher, MPS I, MPS II, and MPS VI diseases have been incorporated into nationwide newborn screening panels in Taiwan.

• Journal of mucopolysaccharidosis and rare diseases
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• v.3 no.1
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• pp.9-13
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• 2017

Tandem mass spectrometry and other new technologies for the multiplex and quantitative analysis of dried blood spots have emerged as powerful techniques for the early screening and assessment of newborns for lysosomal storage diseases (LSDs). Screening newborns for these diseases is important, since treatment options, including enzyme replacement therapy or hematopoietic transplantation, are available for some LSDs, such as infant-onset Pompe disease, Fabry disease, some types of mucopolysaccharidoses (MPSs), and Krabbe disease. For these diseases, early initiation of treatment, before symptoms worsen, often leads to better clinical outcomes. Several problems, however, are associated with newborn screening for LSDs, including the development of accurate test methods to reduce low false-positive rates and treatment guidelines for late-onset or mild disease variants, the high costs associated with multiplex assays, and ethical issues. In this review, we discuss the history, current status, and ethical problems associated with the newborn screening for LSDs, including MPSs.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.3
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• pp.231-240
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• 2023

Fabry disease is a lysosomal storage disorder characterized by the lysosomal accumulations of glycosphingolipids in a variety of cytotypes, which include endothelial cells. The disease is inherited and originates from an error in glycosphingolipid catabolism caused by insufficient α-galactosidase A activity, which causes uncontrolled progressive storage of intracellular globotriaosylceramide (Gb3) in the vasculature and extracellular accumulation of lyso-Gb3 (a deacetylated soluble form of Gb3). Necrosis can lead to inflammation, which exacerbates necrosis and creates a positive feedback loop that triggers necroinflammation. However, the role played by necroptosis, a form of programmed necrotic cell death, in the cell-to-cell inflammatory reaction between epithelial and endothelial cells is unclear. Thus, the present study was undertaken to determine whether lyso-Gb3 induces necroptosis and whether necroptosis inhibition protects endothelial dysfunction against lyso-Gb3 inflamed retinal pigment epithelial cells. We found lyso-Gb3 induced necroptosis of a retinal pigment epithelial cell line (ARPE-19) in an autophagy-dependent manner and that conditioned media (CM) from ARPE-19 cells treated with lyso-Gb3 induced the necroptosis, inflammation, and senescence of human umbilical vein endothelial cells. In addition, a pharmacological study showed CM from lyso-Gb3 treated ARPE-19 cells induced endothelial necroptosis, inflammation, and senescence were significantly inhibited by an autophagy inhibitor (3-MA) and by two necroptosis inhibitors (necrostatin and GSK-872), respectively. These results demonstrate lyso-Gb3 induces necroptosis via autophagy and suggest that lyso-Gb3 inflamed retinal pigment epithelial cells trigger endothelial dysfunction via the autophagy-dependent necroptosis pathway. This study suggests the involvement of a novel autophagy-dependent necroptosis pathway in the regulation of endothelial dysfunction in Fabry disease.

• Proceedings of the Zoological Society Korea Conference
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• 1997.10b
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• pp.261.1-261
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• 1997

No Abstract, See Full Text

• Journal of The Korean Society of Inherited Metabolic disease
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• v.14 no.2
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• pp.135-141
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• 2014

Objectives: Fabry disease (FD) is a lysosomal storage disease caused by the inappropriate accumulation of globotriaosylceramide (Gb3) in tissues due to a deficiency in the enzyme ${\alpha}$-galactosidase A. Hypertrophic cardiomyopathy is one of the chronic complications of FD. We tried to evaluate the prevalence of Fabry disease in the Korean patients with left ventricular hypertrophy (LVH). Methods: A total of 257 patients with LVH were recruited and they were 172 males (mean 56 years, range 30-81 years) and 84 females (mean 66 years, range 45-85 years). Urinary Gb3 was used to screen FD by high performance liquid chromatography-tandem mass spectrometry. Confirmatory tests were done by alpha-galactosidaseA activity using fluorometric assay and by GLA mutation analysis using sequencing. Results: Four patients were screening positive by urinary Gb3 analysis (cutoff, 25 ug/mmol creatinine). But, one female patient was diagnosed with FD confirmed by enzyme analysis in leukocytes as well as by genetic analysis (1/257 patients, 0.4%). She showed 54.3 ug/mmoL creatinine of Gb3 and 15.5 nmole/hr/mg protein (reference range, $55.2{\pm}12.7nmole/hr/mg$ protein) of alphagalactosidase A activity. And she had a heterozygous GLA mutation of c.796G>A (p.D266N). Her daughter was found to be a carrier for FD confirmed by GLA mutation analysis. Asymptomatic carrier showed 25.5ug/mmol creatinine of Gb3 and 42.5 nmole/hr/mg protein (reference range, $55.2{\pm}12.7nmole/hr/mg$ protein) of alpha-galactosidase A activity. Conclusions: The prevalence of FD in Koran patients with LVH was detected as 0.4%. Although the prevalence seems to be low, screening studies are of great importance for detecting hidden cases as well as for identifying other effected family members.

• Korean Journal of Radiology
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• v.23 no.12
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• pp.1251-1259
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• 2022

Objective: T1 mapping provides valuable information regarding cardiomyopathies. Manual drawing is time consuming and prone to subjective errors. Therefore, this study aimed to test a DL algorithm for the automated measurement of native T1 and extracellular volume (ECV) fractions in cardiac magnetic resonance (CMR) imaging with a temporally separated dataset. Materials and Methods: CMR images obtained for 95 participants (mean age ± standard deviation, 54.5 ± 15.2 years), including 36 left ventricular hypertrophy (12 hypertrophic cardiomyopathy, 12 Fabry disease, and 12 amyloidosis), 32 dilated cardiomyopathy, and 27 healthy volunteers, were included. A commercial deep learning (DL) algorithm based on 2D U-net (Myomics-T1 software, version 1.0.0) was used for the automated analysis of T1 maps. Four radiologists, as study readers, performed manual analysis. The reference standard was the consensus result of the manual analysis by two additional expert readers. The segmentation performance of the DL algorithm and the correlation and agreement between the automated measurement and the reference standard were assessed. Interobserver agreement among the four radiologists was analyzed. Results: DL successfully segmented the myocardium in 99.3% of slices in the native T1 map and 89.8% of slices in the post-T1 map with Dice similarity coefficients of 0.86 ± 0.05 and 0.74 ± 0.17, respectively. Native T1 and ECV showed strong correlation and agreement between DL and the reference: for T1, r = 0.967 (95% confidence interval [CI], 0.951-0.978) and bias of 9.5 msec (95% limits of agreement [LOA], -23.6-42.6 msec); for ECV, r = 0.987 (95% CI, 0.980-0.991) and bias of 0.7% (95% LOA, -2.8%-4.2%) on per-subject basis. Agreements between DL and each of the four radiologists were excellent (intraclass correlation coefficient [ICC] of 0.98-0.99 for both native T1 and ECV), comparable to the pairwise agreement between the radiologists (ICC of 0.97-1.00 and 0.99-1.00 for native T1 and ECV, respectively). Conclusion: The DL algorithm allowed automated T1 and ECV measurements comparable to those of radiologists.