• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.38-38
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• 2005

• Journal of the Korean Orthopaedic Association
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• v.55 no.1
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• pp.85-89
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• 2020

Bow hunter's syndrome is a rare disease that shows the symptoms of vertebrobasilar insufficiency resulting from a dynamic obstruction or stenosis of the vertebral arteries during neck movement. This paper reports a case of a 59-year-old male who visited the emergency room with diplopia, tinnitus, and gait disturbance. Magnetic resonance imaging and angiography revealed a multiple cerebellar infarct, total obstruction of the right vertebral artery, and dynamic obstruction of the left vertebral artery during neck extension. As the infarction worsened, a thrombectomy was done. Posterior decompression and fusion at C5-6 were performed for the left vertebral artery. The left vertebral arterial patency was confirmed by intraoperative and postoperative angiography. No recurrence of the symptoms was observed for six months after surgery. Physicians need to pay attention to the diagnosis of vertebrobasilar insufficiency caused by an obstruction of the vertebral arteries during neck extension in cervical instability patients.

• Clinical and Experimental Pediatrics
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• v.55 no.3
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• pp.88-92
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• 2012

Purpose: Mucopolysaccharidosis type II (MPS II or Hunter syndrome) is a rare lysosomal storage disorder caused by iduronate-2-sulfatase (IDS) deficiency. MPS II causes a wide phenotypic spectrum of symptoms ranging from mild to severe. IDS activity, which is measured in leukocyte pellets or fibroblasts, was reported to be related to clinical phenotype by Sukegawa-Hayasaka et al. Measurement of residual plasma IDS activity using a fluorometric assay is simpler than conventional measurements using skin fibroblasts or peripheral blood mononuclear cells. This is the first study to describe the relationship between plasma IDS activity and clinical phenotype of MPS II. Methods: We hypothesized that residual plasma IDS activity is related to clinical phenotype. We classified 43 Hunter syndrome patients as having attenuated or severe disease types based on clinical characteristics, especially intellectual and cognitive status. There were 27 patients with the severe type and 16 with the attenuated type. Plasma IDS activity was measured by a fluorometric enzyme assay using 4-methylumbelliferyl- ${\alpha}$-iduronate 2-sulphate. Results: Plasma IDS activity in patients with the severe type was significantly lower than that in patients with the attenuated type ($p$=0.006). The optimal cut-off value of plasma IDS activity for distinguishing the severe type from the attenuated type was 0.63 $nmol{\cdot}4hr^{-1}{\cdot}mL^{-1}$. This value had 88.2% sensitivity, 65.4% specificity, and an area under receiver-operator characteristics (ROC) curve of 0.768 (ROC curve analysis; $p$=0.003). Conclusion: These results show that the mild phenotype may be related to residual lysosomal enzyme activity.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.4
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• pp.412-417
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• 2012

Mucopolysaccharidosis (MPS) is a disorder which is caused by the defect of the lysosomal enzyme that is essentially needed for resolution of glycosaminoglycans (GAGs). Metabolite of GAGs will accumulate in the lysosome of cells and will result in the dysfunction of cells, tissues, and organs. Eventually, patients will manifest both mental retardation and physical disorders. In worst cases, mucopolysaccharidosis can cause premature death. The current clinical types have been classified as MPS from type I to type IX according to the defect of certain enzyme. The dental complications have been reported as delay of eruption, enamel hypoplasia, microdontia, malocclusion, condylar defects, gingival hyperplasia and dentigerous cystlike follicle. This clinical report presents the case of a boy with MPS type II, Hunter Syndrome which has various dental complications.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.2
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• pp.196-203
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• 2002

Most dentigerous cysts are solitary. Bilateral and multiple dentigerous cysts are rare and occur typically in association with a number of syndromes such as Maroteaux-Lamy syndrome, Hunter's syndrome, Basal cell nevus syndrome, Marfan syndrome, cleidocranial dysplasia. The presented case is of bilateral nonsyndromic, dentigerous cysts associated with mandibular right and left first premolars. A marsupialization procedure may be a choice of treatment for a large sized dentigerous cyst rather than an enucleation. The marsupialization procedure is recommended during the age when the erupting force of the teeth is still strong. We can expect the unerupted tooth to erupt normally. Although most of bilateral or multiple dentigerous cysts which are not associated with syndromes are rare, a bilateral dentigerous cyst without syndrome is seen. Therefore, it is wise to explain a possibility of development of new one to patient / parents in advance.

• Journal of mucopolysaccharidosis and rare diseases
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• v.5 no.1
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• pp.17-21
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• 2021

Hunter syndrome or mucopolysaccharidosis type II (MPS-II) (OMIM 309900) is a rare lysosomal storage disorder caused by deficiency in the activity of the enzyme iduronate-2-sulfatase. This enzyme is responsible for the catabolism of the following two different glycosaminoglycans (GAGs): dermatan sulfate and heparan sulfate. The lysosomal accumulation of these GAG molecules results in cell, tissue, and organ dysfunction. Patients can be broadly classified as having one of the following two forms of MPS II: a severe form and an attenuated form. In the severe form of the disease, signs and symptoms (including neurological impairment) develop in early childhood, whereas in the attenuated form, signs and symptoms develop in adolescence or early adulthood, and patients do not experience significant cognitive impairment. The involvement of the skeletal-muscle system is because of essential accumulated GAGs in joints and connective tissue. MPS II has many clinical features and includes two recognized clinical entities (mild and severe) that represent two ends of a wide spectrum of clinical severities. However, enzyme replacement therapy is likely to have only a limited impact on bone and joint disease based on the results of MPS II studies. The aim of this study was to review the involvement of joints in MPS II.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.18 no.2
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• pp.62-67
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• 2018

Hunter syndrome, also known as mucopolysaccharidosis Type II (MPS II), is one of the lysosomal storage diseases caused by a lack of the enzyme iduronate 2-sulfatase (I2S). Lack of the I2S enzyme activity leads to accumulation of the glycosaminoglycans (GAG), causing dysfunction of multiple organs and systems. MPS II is an X-linked recessive disease due to mutation of IDS gene located on long arm of the X chromosome (Xq28). To date, more than 350 mutations of IDS gene have been identified in Hunter syndrome. Phenotypes of MPS II are classified as either severe or attenuated depending on the degree of cognitive impairment. Because the phenotype of MPS II is related to the type of mutation, identifying mutations is useful in predicting prognosis. We recently had a case of MPS II diagnosed by exome sequencing in a 7 month old boy with infantile spasm uncontrolled by AED. He was diagnosed with hearing loss at 2 months of age, and he took vigabatrin and prednisolone to control infantile spasms diagnosed at 3 months of age. At 6 months of age, whole exome sequencing was performed to evaluate the infantile spasm and hearing loss in this patient, and the mutation c.851C>T (p.Pro284Leu) inherited from hemizygous mother was revealed. The results of urine Cetylpyridinium Chloride (CPC) precipitation test, which were negative until 8 months of age, were positive from 9 months of age. We report a case of MPS II diagnosed by exome sequencing and treated through enzyme replacement therapy from 9 months after birth.

• Clinical and Experimental Pediatrics
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• v.51 no.6
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• pp.650-654
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• 2008

Glycogen storage disease (GSD) and mucopolysaccharidosis (MPS) are both independently inherited disorders. GSD is a member of a group of genetic disorders involving enzymes responsible for the synthesis and degradation of glycogen. GSD leads to abnormal tissue concentrations of glycogen, primarily in the liver, muscle, or both. MPS is a member of a group of inherited lysosomal storage diseases, which result from a deficiency in specific enzymatic activities and the accumulation of partially degraded acid mucopolysaccharides. A case of a 16-month-old boy who presented with hepatomegaly is reported. The liver was four finger-breadth-palpable. A laboratory study showed slightly increased serum AST and ALT levels. The liver biopsy showed microscopic features compatible with GSD. The liver glycogen content was 9.3% which was increased in comparison with the reference limit, but the glucose-6-phosphatase activity was within the normal limit. These findings suggested GSD other than type I. Bony abnormalities on skeletal radiographs, including an anterior beak and hook-shaped vertebrae, were seen. The mucopolysaccharide concentration in the urine was increased and the plasma iduronate sulfatase activity was low, which fulfilled the diagnosis criteria for Hunter syndrome (MPS type II). To the best of the authors' knowledge, this is the first case of GSD and Hunter syndrome being identified at the same time.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.15 no.2
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• pp.87-92
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• 2015

Mucopolysaccharidosis (MPS) is an inherited disease entity associated with lysosomal enzyme deficiencies. MPS type 2, also known as Hunter syndrome, has a characteristic morphology primarily involving x-l inked recessive defects and iduronate-2-sulfatase gene mutation. The purpose of this case report is to provide important clues to help pediatricians identify Hunter syndrome patients earlier (i.e., before the disease progresses). A 30-month-old boy showed developmental delay and decreased speech ability. Physical examinations revealed a flat nose and extensive Mongolian spots. Brain magnetic resonance images (MRIs) showed bilateral multiple patchy T2 hyperintense lesions in the periventricular and deep white matter, several cyst-like lesions in the body of the corpus callosum, and diffuse brain atrophy, which were in keeping with the diagnosis. Based on these findings, the patient was suspected of having MPS. In the laboratory findings, although the genetic analysis of IDS (Iduronate-2-sulfatase) did not show any pathogenic variant, the enzymatic activity of IDS was not detected. We could confirm the diagnosis of MPS, because other sulfatases, such as ${\alpha}$-L-iduronidase, were detected in the normal range. Early enzymatic replacement therapy is essential and has a relatively good prognosis. Therefore, early diagnosis should be made before organ damage becomes irreversible, and brain MRIs can provide additional diagnostic clues to help distinguish the disorder.

• Clinical and Experimental Pediatrics
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• v.48 no.10
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• pp.1132-1138
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• 2005

Purpose : The mucopolysaccharidoses (MPSs) are a heterogeneous group of lysosomal storage disorders. They are caused by a deficiency of the enzymes involved in the degradation of glycosaminoglycans. Early recognition is important because recombinant enzyme replacement therapy is now available for MPS. We studied the clinical characteristics of 80 MPS children with the object of determining the epidemiological, clinical and radiological features in Korean MPS children. Methods : Diagnosis of MPS was confirmed by skin fibroblast enzyme analysis in 80 patients between February 1995 and December 2004. Charts were retrospectively reviewed for clinical and radiological findings, as well as for intelligence and speech evaluations. Results : Hunter syndrome (MPS type II) was the most prevalent type, appearing in 51/80 cases (64 %), followed by Sanfilippo syndrome (MPS III-18%), Hurler syndrome (MPS I-15%), and Morquio syndrome (MPS IV-4%). The average age at diagnosis was 5.5 years (range 1 to 20), and the male-to-female ratio was 4.7 : 1. Typical radiographic changes were observed in 45/54 cases (83%). Mitral regurgitation was the most common cardiac defect. Moderate to profound mental retardation and hearing loss were present in 14/35 cases (56%) and 33/38 cases (82%), respectively. Four MPS II patients had bone marrow transplantation, with mixed outcomes. Five MPS I patients are currently on enzyme replacement therapy. Conclusion : Our study showed a high proportion of MPS II cases (64%), which may represent population variability. By studying the clinical features of these patients, we hope to alert pediatricians of the warning signs of MPS.