Thirty-year clinical outcomes after haematopoietic stem cell transplantation in neuronopathic Gaucher disease.

Background: Neuronopathic Gaucher Disease (nGD) describes the condition of a subgroup of patients with the Lysosomal Storage Disorder (LSD), Gaucher disease with involvement of the central nervous system (CNS) which results from inherited deficiency of β-glucosylceramidase. Although systemic manifestations of disease are now corrected by augmentation with macrophage-targeted therapeutic enzyme (enzyme replacement therapy, ERT), neurological disease progresses unpredictably as a result of failure of therapeutic enzyme to cross the blood-brain barrier (BBB). Without therapy, the systemic and neurological effects of the disease progress and shorten life: investigators, principally in Sweden and the UK, pioneered bone marrow transplantation (BMT; Haematopoietic Stem Cell Transplantation HSCT) to supply healthy marrow-derived macrophages and other cells, to correct the peripheral disease.

The definition of neuronopathic Gaucher disease.

Neuronopathic Gaucher disease (nGD) has a very wide clinical and genotypic spectrum. However, there is no consensus definition of nGD, including no description of how best to diagnostically separate the acute form-Gaucher type 2-from the subacute or chronic form-Gaucher type 3. In this article, we define the various forms of Gaucher disease with particular emphasis on the presence of gaze palsy in all patients with nGD.

Evaluation of impact of anti-idursulfase antibodies during long-term idursulfase enzyme replacement therapy in mucopolysaccharidosis II patients.

Objectives: This 109-week, nonrandomized, observational study of mucopolysaccharidosis II (MPS II) patients already enrolled in the Hunter Outcome Survey (HOS) (NCT00882921), assessed the long-term immunogenicity of idursulfase, and examined the effect of idursulfase-specific antibody generation on treatment safety (via infusion-related adverse events [IRAEs]) and pharmacodynamics (via urinary glycosaminoglycans [uGAGs]).

Methods: Male patients ≥ 5 years, enrolled in HOS regardless of idursulfase treatment status were eligible. Blood/urine samples for anti-idursulfase antibody testing and uGAG measurement were collected every 12 weeks.

Long-term hematological, visceral, and growth outcomes in children with Gaucher disease type 3 treated with imiglucerase in the International Collaborative Gaucher Group Gaucher Registry.

In Gaucher disease (GD), deficiency of lysosomal acid β-glucosidase results in a broad phenotypic spectrum that is classified into three types based on the absence (type 1 [GD1]) or presence and severity of primary central nervous system involvement (type 2 [GD2], the fulminant neuronopathic form, and type 3 [GD3], the milder chronic neuronopathic form). Enzyme replacement therapy (ERT) with imiglucerase ameliorates and prevents hematological and visceral manifestations in GD1, but data in GD3 are limited to small, single-center series. The effects of imiglucerase ERT on hematological, visceral and growth outcomes (note: ERT is not expected to directly impact neurologic outcomes) were evaluated during the first 5years of treatment in 253 children and adolescents (<18years of age) with GD3 enrolled in the International Collaborative Gaucher Group (ICGG) Gaucher Registry.

Long-Term Cognitive and Functional Outcomes in Children with Mucopolysaccharidosis (MPS)-IH (Hurler Syndrome) Treated with Hematopoietic Cell Transplantation.

The long-term cognitive and functional outcomes of children with mucopolysaccharidosis type I (MPS-IH) post-hematopoietic cell transplant (HCT) are not well documented, and the role of genetic and treatment factors in these outcomes has yet to be defined. In this multi-site, international study, we (1) characterize the cognitive and functional status of 47 individuals (ages 2-25, mean of 10.6 years) with MPS-IH who are 1-24 years post HCT (mean = 9 years) and (2) examine contributions of genotype, transplant characteristics, and sociodemographic factors to cognitive ability, adaptive behavior, and quality of life.

Response of 33 UK patients with infantile-onset Pompe disease to enzyme replacement therapy.

Background: Enzyme replacement therapy (ERT) for infantile-onset Pompe disease has been commercially available for almost 10 years. We report the experience of its use in a cohort treated at three specialist lysosomal treatment centres in the UK.

Methods: A retrospective case-note review was performed, with additional data being gathered from two national audits on all such patients treated with ERT.

Longitudinal analysis of endurance and respiratory function from a natural history study of Morquio A syndrome.

Objectives: Baseline data from the Morquio A Clinical Assessment Program (MorCAP) revealed that individuals with Morquio A syndrome show substantial impairment in multiple domains including endurance and respiratory function (Harmatz et al., Mol Genet Metab, 2013). Here, 1- and 2-year longitudinal endurance and respiratory function data are presented.

Exome sequencing identifies CTSK mutations in patients originally diagnosed as intermediate osteopetrosis.

Autosomal Recessive Osteopetrosis is a genetic disorder characterized by increased bone density due to lack of resorption by the osteoclasts. Genetic studies have widely unraveled the molecular basis of the most severe forms, while cases of intermediate severity are more difficult to characterize, probably because of a large heterogeneity. Here, we describe the use of exome sequencing in the molecular diagnosis of 2 siblings initially thought to be affected by "intermediate osteopetrosis", which identified a homozygous mutation in the CTSK gene.

Successful Desensitisation in a Patient with CRIM-Positive Infantile-Onset Pompe Disease.

Pompe disease (PD) is a severe life-threatening disease in which enzyme replacement therapy (ERT) with alglucosidase alfa is the only treatment available. Recently it has been shown that antibody formation may have a significant adverse effect on response to ERT. We report a cross-reactive immunologic material (CRIM)-positive PD infant who developed severe infusion-associated reactions (IARs) after 15 uneventful months of ERT.

A Clinically Severe Variant of β-Mannosidosis, Presenting with Neonatal Onset Epilepsy with Subsequent Evolution of Hydrocephalus.

β-Mannosidosis results from a functional deficiency of the lysosomal enzyme, β-mannosidase. While being a well recognised, naturally occurring disease in both goats and cattle, it is an extremely rare disorder in humans with the first cases only being recorded in 1986. Until now the severity of the human disease has not mirrored that of its bovine or caprine counterparts, whose presentation is typically in the neonatal period with both altered skull morphology and seizures.

The Morquio A Clinical Assessment Program: baseline results illustrating progressive, multisystemic clinical impairments in Morquio A subjects.

Objectives: The objectives of this study are to quantify endurance and respiratory function and better characterize spectrum of symptoms and biochemical abnormalities in mucopolysaccharidosis IVA subjects.

Methods: MorCAP was a multicenter, multinational, cross sectional study amended to be longitudinal in 2011. Each study visit required collection of medical history, clinical assessments, and keratan sulfate (KS) levels.

SNX10 mutations define a subgroup of human autosomal recessive osteopetrosis with variable clinical severity.

Human Autosomal Recessive Osteopetrosis (ARO) is a genetically heterogeneous disorder caused by reduced bone resorption by osteoclasts. In 2000, we found that mutations in the TCIRG1 gene encoding for a subunit of the proton pump (V-ATPase) are responsible for more than one-half of ARO cases. Since then, five additional genes have been demonstrated to be involved in the pathogenesis of the disease, leaving approximately 25% of cases that could not be associated with a genotype.

Increased glucocerebrosidase (GBA) 2 activity in GBA1 deficient mice brains and in Gaucher leucocytes.

Lysosomal glucocerebrosidase (GBA1) deficiency is causative for Gaucher disease. Not all individuals with GBA1 mutations develop neurological involvement raising the possibility that other factors may provide compensatory protection. One factor may be the activity of the non-lysosomal β-glucosidase (GBA2) which exhibits catalytic activity towards glucosylceramide and is reported to be highly expressed in brain tissue.

The effectiveness and cost-effectiveness of enzyme and substrate replacement therapies: a longitudinal cohort study of people with lysosomal storage disorders.

Objectives: To determine natural history and estimate effectiveness and cost of enzyme replacement therapy (ERT) and substrate replacement therapy (SRT) for patients with Gaucher disease, Fabry disease, mucopolysaccharidosis type I (MPS I), mucopolysaccharidosis type II (MPS II), Pompe disease and Niemann-Pick type C (NPC) disease.

Design: Cohort study including prospective and retrospective clinical- and patient-reported data. Age- and gender-adjusted treatment effects were estimated using generalised linear mixed models.

RANK-dependent autosomal recessive osteopetrosis: characterization of five new cases with novel mutations.

Autosomal recessive osteopetrosis (ARO) is a genetically heterogeneous disorder attributed to reduced bone resorption by osteoclasts. Most human AROs are classified as osteoclast rich, but recently two subsets of osteoclast-poor ARO have been recognized as caused by defects in either TNFSF11 or TNFRSF11A genes, coding the RANKL and RANK proteins, respectively. The RANKL/RANK axis drives osteoclast differentiation and also plays a role in the immune system.

Enzyme replacement therapy and/or hematopoietic stem cell transplantation at diagnosis in patients with mucopolysaccharidosis type I: results of a European consensus procedure.

Background: Mucopolysaccharidosis type I (MPS I) is a lysosomal storage disorder that results in the accumulation of glycosaminoglycans causing progressive multi-organ dysfunction. Its clinical spectrum is very broad and varies from the severe Hurler phenotype (MPS I-H) which is characterized by early and progressive central nervous system (CNS) involvement to the attenuated Scheie phenotype (MPS I-S) with no CNS involvement. Indication, optimal timing, safety and efficacy of the two available treatment options for MPS I, enzyme replacement therapy (ERT) and hematopoietic stem cell transplantation (HSCT), are subject to continuing debate.

Urine analysis of glucose tetrasaccharide by HPLC; a useful marker for the investigation of patients with Pompe and other glycogen storage diseases.

A high performance liquid chromatography method, adapted from an established urinary sugars method, has been developed for the analysis of a tetraglucose oligomer (Glc(4)) in urine. Pompe disease results from defects in the activity of lysosomal acid α-glucosidase (GAA) with patients typically excreting increased amounts of Glc(4). Rapid determination of GAA in dried blood spots is now possible.

Four-year follow-up of chronic neuronopathic Gaucher disease in Europeans using a modified severity scoring tool.

In 2007, the European Task Force for neuronopathic Gaucher disease (NGD) published a review of 55 patients across four countries. Although some observations were possible, analysis was difficult due to the absence of a systematic way of assessing patients. In response to this, a Severity Scoring Tool (SST) was devised to offer a systematic means of assessing the neurological presentation seen.

Treatment of mucopolysaccharidosis type II (Hunter syndrome) with idursulfase: the relevance of clinical trial end points.

The current treatment of mucopolysaccharidosis type II (MPS II, Hunter syndrome) is enzyme replacement therapy with recombinant idursulfase (Elaprase®). The efficacy of ERT was established based primarily on reduction in urine glycosaminoglycans:creatinine (GAG:Cr) ratio and improvement in a composite score of predicted forced vital capacity (FVC% predicted) and 6-min walk-test distance (6MWT). We retrospectively reviewed these parameters in 11 boys with MPS II treated with idursulfase between April 2007 (or the time of diagnosis) and February 2010.

Brain white matter abnormalities in paediatric Gaucher Type I and Type III using diffusion tensor imaging.

Objective: Biomarkers to monitor neurological dysfunction in Neuronopathic Gaucher disease (NGD) are lacking. Diffusion tensor imaging (DTI) is a technique which allows us to probe the microstructure of the white-matter of the brain, in-vivo. The aim of this study was to investigate the value of DTI to visualise and quantify white matter integrity in children with NGD and Type I Gaucher.

Idursulfase treatment of Hunter syndrome in children younger than 6 years: results from the Hunter Outcome Survey.

Purpose: To use the Hunter Outcome Survey, an international database, to assess the safety and effectiveness of enzyme replacement therapy with idursulfase in patients with Hunter syndrome who started treatment before 6 years of age.

Methods: The study population included all patients enrolled in the Hunter Outcome Survey who started idursulfase infusions (0.5 mg/kg every other week) before 6 years of age and who had at least one follow-up examination recorded.

Long-term, open-labeled extension study of idursulfase in the treatment of Hunter syndrome.

Purpose: This study evaluated the safety and effectiveness of long-term enzyme replacement therapy with idursulfase (recombinant human iduronate-2-sulfatase) in patients with Hunter syndrome.

Methods: All 94 patients who completed a 53-week double-blinded study of idursulfase enrolled in this open-labeled extension study and received intravenous idursulfase at a dose of 0.5 mg/kg weekly for 2 years, and clinical outcomes and safety were assessed.

Treatment of infantile Pompe disease with alglucosidase alpha: the UK experience.

Treatment of infantile Pompe disease with recombinant human acid α-glucosidase has shown substantial improvement in survival, and in cardiac, motor and respiratory functions. We analyzed the outcome of all patients with infantile Pompe disease treated in the United Kingdom since the availability of the enzyme, using a questionnaire-based survey circulated to all treating centres. A total of 20 infants were treated from 2000 to 2009.

Pulmonary hemorrhage in type 3 Gaucher disease: a case report.

A 2-year-old boy with type 3 Gaucher disease (GD) on treatment with enzyme replacement therapy (ERT) was found dead in bed having been apparently well the night before. At the time of diagnosis, he had significant respiratory symptoms (severe and persistent bouts of coughing) that had been attributed to Gaucher lung infiltration and that were controlled by inhaled and orally administered steroids. These symptoms had begun to reappear just prior to death.