An empowered, clinically viable hematopoietic stem cell gene therapy for the treatment of multisystemic mucopolysaccharidosis type II.

Mucopolysaccharidosis type II (MPS II), or Hunter syndrome, is a rare X-linked recessive lysosomal storage disorder due to a mutation in the lysosomal enzyme iduronate-2-sulfatase (IDS) gene. IDS deficiency leads to a progressive, multisystem accumulation of glycosaminoglycans (GAGs) and results in central nervous system (CNS) manifestations in the severe form. We developed up to clinical readiness a new hematopoietic stem cell (HSC) gene therapy approach for MPS II that benefits from a novel highly effective transduction protocol. We first provided proof of concept of efficacy of our approach aimed at enhanced IDS enzyme delivery to the CNS in a murine study of immediate translational value, employing a lentiviral vector (LV) encoding a codon-optimized human IDS cDNA. Then the therapeutic LV was tested for its ability to efficiently and safely transduce bona fide human HSCs in clinically relevant conditions according to a standard vs. a novel protocol that demonstrated superior ability to transduce bona fide long-term repopulating HSCs. Overall, these results provide strong proof of concept for the clinical translation of this approach for the treatment of Hunter syndrome.

Hallazgos tempranos y tardíos en la resonancia cerebral de dos hermanos con síndrome de Hunter / Early and late brain resonance findings of two siblings with Hunter syndrome

Introducción: La mucopolisacaridosis de tipo II (MPS II) es una enfermedad lisosómica causada por deficiencia de la enzima iduronato-2-sulfatasa, ligada al cromosoma X, y produce un gran espectro de manifestaciones clínicas. Caso clínico: Se presenta el caso clínico de dos hermanos con MPS II de diferente origen paterno con la misma mutación genética; la edad en el momento del diagnóstico fue de 5 años (caso 1) y de 8 meses (caso 2). Dichos hermanos presentan hallazgos diferentes en la resonancia magnética cerebral entre sí: el caso 1 presentó hallazgos clásicos para la edad, y el caso 2 presentó múltiples hallazgos tempranos, como espacios perivasculares dilatados de hasta 9,5 mm y megacisterna magna, entre otros, sin presentar manifestaciones neurológicas. Conclusiones: La afectación cerebral del paciente del caso 2 se presentó antes del año de edad y previa a la hepatoesplenomegalia. La resonancia magnética se convierte en una herramienta de diagnóstico temprano para la MPS II.(AU)

Introduction: Mucopolysaccharidosis type II (MPS II) is a lysosomal disease caused by deficiency of the enzyme iduronate-2-sulfatase (IDS), linked to the X chromosome, producing a wide spectrum of clinical manifestations. Case report: We present the case of two siblings with MPS II of different paternal origin with the same genetic mutation; the age at the time of diagnosis was 5 years of age (case 1) and 8 months of age (case 2). These brethren present different findings in brain magnetic resonance imaging (MRI) with each other, case 1 presented classic findings for age, case 2 presented multiple early findings, such as dilated perivascular spaces up to 9.5 mm, magna megacisterna, among others; without neurological manifestations. Conclusion: This patient’s brain compromise was presented before the year of age and prior to hepatosplenomegaly, thus, MRI becomes an early diagnostic tool for MPS II.(AU)

Mutation analysis of mucopolysaccharidosis type Ⅱ and prenatal diagnosis / 中华妇产科杂志

Objective To analyze the mutations of IDS gene in a mucopolysaccharidosis type Ⅱ (MPS Ⅱ) family and to make prenatal diagnosis on the high-risk fetus which has been pregnant for eleven weeks.Methods IDS gene was analyzed by bidirectional DNA sequencing in 2 patients and their mother,and 5 unaffected individuals.Prenatal diagnosis for the high-risk fetus was performed by chorionic villus sampling after the genotypes was identified.Results The mutation c.344delA (N115fsX15) was detected in the two patients,and the mother of patients carried the heterozygous c.344delA (N115fsX15) mutation.None of the mutant was detected in the 5 unaffected subjects.The fetus carried c.344delA (N115fsX15) heterozygous mutation and was a carrier.Conclusion The deletion mutation c.344delA (N115fsX15) is causative to the pedigree of MPS Ⅱ,and prenatal diagnosis is the efficient method to avoid defect birth.

A study of the relationship between clinical phenotypes and plasma iduronate-2-sulfatase enzyme activities in Hunter syndrome patients.

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-α-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·4 hr(-1)·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.

A study of the relationship between clinical phenotypes and plasma iduronate-2-sulfatase enzyme activities in Hunter syndrome patients / 소아과

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.4 hr-1.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.

A study of the relationship between clinical phenotypes and plasma iduronate-2-sulfatase enzyme activities in Hunter syndrome patients / 소아과

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.4 hr-1.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.

Síndrome de Hunter Mucopolisacaridosis (II): reporte de un caso / Hunter Syndrome Mucopolysaccharides (II): a Case Report

El síndrome de Hunter, es una alteración genética que afecta principalmente a los varones, debido a la deficiencia o ausencia de la enzima iduronato-2-sulfatasa, que interfiere con la capacidad del cuerpo de descomponer y reciclar los mucopolisacáridos. La incidencia es de 1: 10.000 a 1:25.000 de recién nacidos vivos. Las manifestaciones físicas, incluyen rasgos faciales distintivos, cabeza grande, abdomen aumentado, engrosamiento de válvulas cardíacas, enfermedad respiratoria obstructiva, retraso del desarrollo mental y aumento de tamaño del hígado y del bazo. Presentamos el caso clínico de un paciente de sexo masculino de 7 años de edad, con diagnostico de síndrome de Hunter hace seis años, con antecedentes de crisis convulsivas en dos oportunidades y cuadros de bronconeumonía. Al examen físico presenta fascie tosca, contractura en musculo bíceps braquial, se logra la extensión de las manos, camina con la punta de los pies y presenta hepato y esplenomegalia. Al cual se le trató la sintomatología respiratoria con el uso de antibióticos.

Hunter Syndrome, is a genetic disorder that primarily affects males, due to the deficiency or absence of the enzyme iduronate-2-sulfatase, which interferes with the ability of the body break down and recyele mucopolysaccharides. The incidence is 1: 10.000 to 1:25.000 babies alive. The physical manifestations includes distinctive facial features, large head, abdomen increased thickening of heart valves, obstructive respiratory illness, delayed mental development and enlarged liver and spleen. We present the clinical case of a 7-year-old male patient with diagnosis of Hunter Syndrome six years ago, with a history of seizures in two occasions and schedules of bronchopneumonia. A physical examination presents rough fascie, brachial bicep muscle contracture, is achieved by the extension of the hands, walks with the tip of toes and presents hepato and splenomegaly. Which we treated respiratory symptoms with the use of antibiotics.