• Journal of mucopolysaccharidosis and rare diseases
• /
• v.3 no.1
• /
• pp.1-8
• /
• 2017

Mucopolysaccharidosis (MPS) type III, or Sanfilippo syndrome is a rare autosomal recessive lysosomal storage disorder. It is caused by a deficiency of one of four enzymes involved in the degradation of the glycosaminoglycan (GAG) heparan sulfate. The resultant cellular accumulation of heparan sulfate causes various clinical manifestations. MPS III is divided into four subtypes depending on the deficient enzyme: MPS IIIA, MPS IIIB, MPS IIIC and MPS IIID. All the subtypes show similar clinical features and are characterized by progressive degeneration of the central nervous system (CNS). Main purpose of the treatment for MPS III is to prevent neurologic deterioration. However, conventional enzyme replacement therapy has a limitation due to inability to cross the blood-brain barrier. Several experimental treatment options for MPS III are being developed.

• Journal of mucopolysaccharidosis and rare diseases
• /
• v.2 no.1
• /
• pp.1-4
• /
• 2016

Mucolipidosis type II (MLII; MIM#252500) and type III alpha/beta (MLIIIA; MIM#252600) very rare lysosomal storage disease cause by reduced enzyme activity of GlcNAc-1-phosphotransferase. ML II is caused by a total or near total loss of GlcNAc-1-phosphotransferase activity whether enzymatic activity in patient with ML IIIA is reduced. While ML II and ML III share similar clinical features, including skeletal abnormalities, ML II is the more severe in terms of phenotype. ML III is a much milder disorder, being characterized by latter onset of clinical symptoms and slower progressive course. GlcNAc-1-phosphotransferase is encoded by two genes, GNPTAB and GNPTG, mutations in GNPTAB give rise to ML II or ML IIIA. To date, more than 100 different GNPTAB mutations have been reported, causing either ML II or ML IIIA. Despite development of new diagnostic approach and understanding of disease mechanism, there is no specific treatment available for patients with ML II and ML IIIA yet, only supportive and symptomatic treatment is indicated.

• Journal of mucopolysaccharidosis and rare diseases
• /
• v.5 no.1
• /
• pp.12-16
• /
• 2021

Mucopolysaccharidosis type II (MPS II, Hunter syndrome) is an X-linked lysosomal storage disorder caused by deficiency of the enzyme iduronate-2-sulfatase, leading to the accumulation of glycosaminoglycans (GAGs), which affects multiple organs and systems. Current treatments for MPS II include enzyme replacement therapy (ERT) and hematopoietic cell transplantation (HCT) to reduce the accumulation of GAGs. HCT has the potential advantage that donor-derived enzyme-competent cells can provide a continuous secreting source of the enzyme. However, HCT as a treatment for MPS II remains controversial because its effectiveness is unclear, particularly in terms of neurological symptoms. To date, several clinical experiences with HCT in MPS II have been reported. In this paper, we review post-HCT outcomes in the previously published literature and discuss the effects of HCT on each of the clinical signs and symptoms of MPS II.

• Clinical and Experimental Pediatrics
• /
• v.49 no.11
• /
• pp.1152-1157
• /
• 2006

Inherited metabolic disease is rare disorders that show symptoms mainly in pediatric age and early treatment is important for preventing complications of the disease. Recent development in molecular and biochemical techniques help clinicians with proper diagnosis of patients, however, many of the disease still remain lack of effective therapeutic strategies. Better understanding on biochemical and molecular basis of pathogenesis of the disease combined with advanced medical care would provide new sight on the disease that can also improve the quality of life and long-term prognosis of patients. Traditionally, there are several modalities in the treatment of metabolic diseases depend on the biochemical basis of the disease such as diet restriction, removing or blocking the production of toxic metabolites, and stimulating residual enzyme activity. The inherited metabolic disease is not familiar for many clinicians because the diagnosis is troublesome, treatment is complicated and prognosis may not as good as expected in other diseases. Recently, new therapeutic regimens have been introduced that can significantly improve the medical care of patients with metabolic disease. Enzyme replacement therapy has showed promising efficacy for lysosomal storage disease, bone marrow transplantation is effective in some disease and gene therapy has been trying for different diseases. The new trials for treatment of the disease will give us promising insight on the disease and most clinicians should have more interest in medical progress of the metabolic disease.

• Journal of Genetic Medicine
• /
• v.15 no.1
• /
• pp.28-33
• /
• 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 mucopolysaccharidosis and rare diseases
• /
• v.4 no.1
• /
• pp.26-36
• /
• 2018

Mucopolysaccharidosis IIIA is a heritable neurodegenerative disorder resulting from the dysfunction of the lysosomal hydrolase sulphamidase. This leads to the primary accumulation of the complex carbohydrate heparan sulphate in a wide range of tissues and CNS degeneration. Characterization of animal model is the beginning point of the therapeutic clinical trial. Mouse model has a limitation in that it is not a human and does not have all of the disease phenotypes. Therefore, delineate of the phenotypic characteristics of MPS IIIA mouse model prerequisite for the enzyme replace treatment for the diseases. We designed 6-month duration of phenotypic characterization of MPS IIIA mouse biochemically, behaviorally and histologically. We compared height and weight of MPS IIIA mouse with wild type from 4 weeks to 6 months in both male and female. At 6 months, we measured GAG storage in urine kidney, heart, liver, lung and spleen. The brain GAG storage is presented with Alcian blue staining, immunohistochemistry, and electron-microscopy. The neurologic phenotype is evaluated by brain MRI and behavioral study including open field test, fear conditioning, T-maze test and Y-maze test. Especially behavioral tests were done serially at 4month and 6month. This study will show the result of the MPS IIIA mouse model phenotypic characterization. The MPS IIIA mouse provides an excellent model for evaluating pathogenic mechanisms of disease and for testing treatment strategies, including enzyme or cell replacement and gene therapy.

• Journal of mucopolysaccharidosis and rare diseases
• /
• v.3 no.1
• /
• pp.33-33
• /
• 2017

• Journal of Genetic Medicine
• /
• v.19 no.1
• /
• pp.32-37
• /
• 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.

• Childhood Kidney Diseases
• /
• v.20 no.2
• /
• pp.79-82
• /
• 2016

Fabry disease is an X-linked lysosomal storage disorder caused by a deficiency of the enzyme ${\alpha}-galactosidase$ A, resulting in the accumulation of glycosphingolipids within the lysosomes of various cell types. It has a wide spectrum of clinical phenotypes, and renal failure is a serious complication. Fabry disease is confirmed either by measurement of ${\alpha}-galactosidase$ A activity or by genetic testing for GLA mutations. Renal biopsy findings on light microscopy, specifically enlarged podocytes with foamy cytoplasm, and osmiophilic inclusion bodies in the cytoplasm in all types of renal cells on electron microscopy, are characteristic of this disease. The predominant differential diagnosis is iatrogenic phospholipidosis in association with certain drugs that can cause cellular injuries indistinguishable from Fabry disease. Here, we report the case of a 10-year-old boy with microscopic hematuria who underwent a renal biopsy that showed morphological findings consistent with Fabry disease, although the patient had neither a GLA mutation nor a history of drug consumption. Six years later, spontaneous regression of this renal pathology was observed in a second renal biopsy examination.

• Korean Journal of Veterinary Research
• /
• v.62 no.4
• /
• pp.27.1-27.4
• /
• 2022

A 2-year-old spayed female Border Collie presented with visual deficits and behavioral changes. Neurological examination revealed bilateral menace response deficit with a normal pupil light reflex. Cerebral cortical thinning, cerebral sulci and cerebellar fissure widening, ventriculomegaly, and cerebral atrophy were observed on magnetic resonance imaging (MRI). Histopathology revealed fluorescent lipopigment accumulation in the cerebrum, and the dog was diagnosed with neuronal ceroid lipofuscinosis. This is the first case report describing the changes in clinical signs, MRI findings, and histopathologic changes in neuronal ceroid lipofuscinosis in Korea.