• Journal of Genetic Medicine
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• 제19권1호
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• pp.32-37
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• 2022

Mucopolysaccharidosis type VI (MPS VI) is an autosomal recessive lysosomal disorder caused by the deficiency of arylsulfatase B due to mutations in the ARSB gene. Here, we report the case of a Korean female with a novel variant of MPS VI. A Korean female aged 5 years and 8 months, who is the only child of a healthy non-consanguineous Korean couple, presented at our hospital for severe short stature. She had a medical history of umbilical hernia and recurrent otitis media. Her symptoms included snoring and mouth breathing. Subtle dysmorphic features, including mild coarse face, joint contracture, hepatomegaly, and limited range of joint motion, were identified. Radiography revealed deformities, suggesting skeletal dysplasia. Growth hormone (GH) provocation tests revealed complete GH deficiency. Targeted exome sequencing revealed compound heterozygous mutations in the ARSB genes c.512G>A (p.Gly171Asp; a pathogenic variant inherited from her father) and c.1157C>T (p.Ser386Phe; a novel variant inherited from her mother in familial genetic testing). Quantitative tests revealed increased urine glycosaminoglycan (GAG) levels and decreased enzyme activity of arylsulfatase B. While on enzyme replacement therapy and GH therapy, her height increased drastically; her coarse face, joint contracture, snoring, and obstructive sleep apnea improved; urine GAG decreased; and left ventricular mass index was remarkably decreased. We report a novel variant-c.1157C>T (p.Ser386Phe)-of the ARSB gene in a patient with MPS VI; these findings will expand our knowledge of its clinical spectrum and molecular mechanisms.

• 대한유전성대사질환학회지
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• 제16권1호
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• pp.24-33
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• 2016

뮤코다당증 6형(Mucopolysaccharidosis type VI)은 ARSB 유전자의 변이로 인하여 dermatan sulfate 대사에 관여하는 arylsulfatase B 효소의 결핍으로 유발되는 상염색체 열성 리소좀 축적 질환이다. 본 연구는 국내에서 뮤코다당증 6형으로 진단된 3명의 환자를 대상으로 하였다 3명의 환자는 최초 진단 시 뮤코다당증 6형의 특징적인 증상인 저신장, 다발성 골형성 부전, 심장 판막 이상 및 각막 혼탁을 보였으며 이후 손목 터널 증후군 및 제한성 폐질환의 양상을 보였다. 모든 환자에서 소변의 GAG (glycosaminoglycan)는 증가되어 있었으며 피부 섬유아세포 또는 백혈구에서 측정한 arylsulfatase B는 모두 감소되어 있었고 중합효소 연쇄반응-염기서열분석법에 의한 ARSB 유전자 검사에서는 c.200T>G (p.Ile67Ser), c.982G>A (p.Gly328Arg), c.571C>T (p.Arg191*), c.1054G>A (p.Asp352Asn)의 이형접합체 돌연변이 및 c.512G>A (p.Gly171Asp) 동형접합체 돌연변이를 발견할 수 있었다. recombinant human Arylsulfatase B (rhASB)를 통한 효소 대체 치료는 2008년부터 국내에서도 허가되었으며 효소대체치료 시행 후 소변 GAG (glyco-saminoglycan)는 감소하였으며 관절 운동 및 지구력은 향상되었다. 그러나 관절 침범 및 각막 혼탁, 심장 및 폐 침범 소견은 호전되지 않았다. 본 연구는 뮤코다당증 6형의 특징적인 증상을 보였으며 생화학적 검사 및 분자유전학적 검사를 통해 뮤코다당증 6형으로 확진된 3명의 환자를 대상으로 시행한 효소대체치료의 효과를 보고하는 바이다.

• Journal of mucopolysaccharidosis and rare diseases
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• 제3권1호
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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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• 제4권1호
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• pp.11-13
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• 2018

In Malaysia, diagnosis and treatment of patients with mucopolysaccharidoses (MPS) is mainly localized at Hospital Kuala Lumpur, which is the national referral center for rare diseases. To date there are 83 patients diagnosed with MPS in our center, with MPS II being the commonest. The Malaysian National Medicines Policy second edition has a specific section on the orphan drugs which includes recombinant human enzyme for enzyme replacement therapy (ERT) in MPS. So far, National Pharmaceutical Regulatory Agency Malaysia has approved recombinant human enzyme for MPS types I (Loranidase), II (idursulfase), IVA (elosulfase alfa), and VI (Galsufase). Access to Idursulfase beta (another recombinant human enzyme for MPS II) and vestronidase alfa-vjbk (MPS VII) required special authorization on named patient basic. Currently there are 25 patients receiving ERT, 70% of the funding are from Ministry of Health (MOH), the remaining 30% are from various charitable funds and humanitarian programs. Thirteen newly diagnosed patients have to queue for an additional fund. Four patients have been treated with Hematopoietic stem cell transplant. MOH has also published guidelines regarding the patient selection criteria for ERT and treatment monitoring schedule.

• 대한유전성대사질환학회지
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• 제14권2호
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• pp.178-181
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• 2014

헌터증후군(뮤코다당증 II형)은 글리코사미노글리칸의 분해를 촉매하는 효소인 iduronate-2-sulfatase 결핍에 의해 조직이나 기관의 세포 내 리소좀에 heparin sulfate와 dermatan sulfate 등의 전구물질이 축적되어 퇴행성 병변을 일으키는 유전 질환이다. 현재 효소보충요법을 통해 증상의 호전 및 질병의 진행을 지연시키는 치료가 가능하나, 중추신경계 증상이 발현된 경우 치료가 어려운 한계가 있어, 무엇보다 조기에 의심하고 진단하여 치료를 시작하는 것이 중요하다. 따라서 어린연령에 진단된 환아들의 임상적 특징에 대해 이해하는 것이 필요하며, 이에 저자들은 2.5세의 어린 연령에 진단된 환아를 경험하여 이를 보고하는 바이다.

• 대한유전성대사질환학회지
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• 제10권1호
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• pp.59-66
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• 2010

Enzyme replacement of therapy (ERT) is one of the most promising therapeutic strategies for the treatment of lysosomal storage disorders. ERT is available in three types of Mucopolysaccharidosis (MPS): for MPS I (Aludrazyme$^{(R)}$), MPS II (Elaprase$^{(R)}$) and MPS VI (Naglazyme$^{(R)}$) patients who are over 5 years old. But recently, early diagnosis can be done by expert clinicians and even in prenatal case. We describe the case of ERT under 5 years old MPS patients. Up to June, 2010 in Samsung Medical Center, there are 6patients who were diagnosed as MPS and started ERT under 5 years old. 3 patients were MPS I, 3 patients were MPS II. 2 patient who was diagnosed as MPS I was female and others were male. Their age at diagnosis were 4 to 37month-old (4, 13, 16, 25, 27, 37 month-old) and they are now 9 to 60 month-old (9, 39, 32, 81, 60 month-old). The youngest patient was started ERT at 4 month-old and others were started at their 13 to 49 month-old (13, 29, 27, 28, 49 month-old). First manifested symptoms of patients were macrocephaly, kyphosis and coarse face appearance. Especially, in 2 of them, one was MPS I and the other was MPS II had elder brother with same disease. And the youngest one was diagnosed by the iduronate-2-sulfatase (IDS) gene analysis from chorionic villi sampling. His mother knew that she was a heterozygous carrier of IDS gene mutation because her younger brother died from MPS II. All of them confirmed as MPS by the enzyme assay in leukocytes and fibroblast skin culture. We started ERT with ${\alpha}$-L-iduronidase(Aldurazyme$^{(R)}$) to MPS I and did recombinant human iduronate-2-sulfatase (Elaprase$^{(R)}$) to MPS II patients as recommended dose as over 5 years old. But for MPS II patient who was 4 month old, we started ERT by recombinant human IDS (Elaprase$^{(R)}$) with reduced dose 0.1 mg/kg and increased dose every 2 weeks by 0.1mg/kg up to 0.5mg/kg IV infusion. During ERT, all patients had no adverse effects and the excretion of GAGs were decreased. We have evaluated other clinical symptoms such as liver/ spleen volume, heart function and neurologic evaluation. We describe a successful ERT to MPS I and MPS II patient under 5 years old without any adverse event. It indicates that ERT in young children are well tolerated and that it has several effects which may confer clinical benefits with long-term therapy.