Mortality in patients with Sanfilippo syndrome.

BACKGROUND: Sanfilippo syndrome (mucopolysaccharidosis type III; MPS III) is an inherited monogenic lysosomal storage disorder divided into subtypes A, B, C and D. Each subtype is characterized by deficiency of a different enzyme participating in metabolism of heparan sulphate. The resultant accumulation of this substrate in bodily tissues causes various malfunctions of organs, ultimately leading to premature death. Eighty-four, 24 and 5 death certificates of patients with Sanfilippo syndrome types A, B and C, respectively, were obtained from the Society of Mucopolysaccharide Diseases (UK) to better understand the natural course of these conditions, covering the years 1977-2007. RESULTS: In Sanfilippo syndrome type A mean age at death (± standard deviation) was 15.22 ± 4.22 years, 18.91 ± 7.33 years for patients with Sanfilippo syndrome type B and 23.43 ± 9.47 years in Sanfilippo syndrome type C. Patients with Sanfilippo syndrome type A showed significant increase in longevity over the period of observation (p = 0.012). Survival rates of patients with Sanfilippo syndrome type B did not show a statistically significant improvement (p = 0.134). In Sanfilippo syndrome types A and B, pneumonia was identified as the leading cause of death. CONCLUSIONS: The analysis of 113 death certificates of patients with Sanfilippo syndrome in the UK has demonstrated that the longevity has improved significantly in patients with Sanfilippo syndrome type A over a last few decades. The numbers of patients with Sanfilippo syndrome types B and C were too small to identify any significant trend changes for these groups. Respiratory tract infections, notably pneumonia, remain the leading cause of mortality in Sanfilippo syndrome types A and B. The extended lifespans of patients with Sanfilippo syndrome type A were achieved despite the lack of therapies to target the primary insult or pathophysiology of the disease. However, the mean age at death of these patients remains low when compared with the general population. Therefore, there is an urgent need for effective disease-specific therapies to be developed so that the quality of life and survival of patients with Sanfilippo syndrome can be improved.

Recommendations on clinical trial design for treatment of Mucopolysaccharidosis Type III.

BACKGROUND: Mucopolysaccharidosis type III is a progressive, neurodegenerative lysosomal storage disorder for which there is currently no effective therapy. Though numerous potential therapies are in development, there are several challenges to conducting clinical research in this area. We seek to make recommendations on the approach to clinical research in MPS III, including the selection of outcome measures and trial endpoints, in order to improve the quality and impact of research in this area. RESULTS: An international workshop involving academic researchers, clinical experts and industry groups was held in June 2015, with presentations and discussions on disease pathophysiology, biomarkers, potential therapies and clinical outcome measures. A set of recommendations was subsequently prepared by a working group and reviewed by all delegates. We present a series of 11 recommendations regarding the conduct of clinical research, outcome measures and management of natural history data in Mucopolysaccharidosis type III. CONCLUSIONS: Improving the quality of clinical research in Mucopolysaccharidosis type III will require an open, collaborative and systematic approach between academic researchers, clinicians and industry. Natural history data should be published as soon as possible and ideally collated in a central repository. There should be agreement on outcome measures and instruments for evaluation of clinical outcomes to maximise the effectiveness of current and future clinical research.

The diagnostic journey of patients with mucopolysaccharidosis I: A real-world survey of patient and physician experiences.

UNLABELLED: Mucopolysaccharidosis type I (MPS I) is an inherited lysosomal storage disease. Affected individuals have disease ranging from attenuated to severe with significant disease burden, disability, and premature death. Early treatment with enzyme replacement therapy and/or stem cell transplantation can reduce disease progression and improve outcomes. However, diagnosis is often delayed, particularly for patients with attenuated phenotypes. We conducted a survey of 168 patients and 582 physicians to explore health care seeking patterns and familiarity of physicians with MPS I symptoms. Patients with attenuated MPS I typically first presented with stiff joints or hernia/bulging abdomen, and patients with severe disease with noisy/difficult breathing, or hernia/bulging abdomen. There was a mean delay from time of symptom presentation to diagnosis of 2.7 years for patients with attenuated disease, with a mean of 5 physicians consulted before receiving a correct diagnosis. MPS I was most commonly misidentified by physicians as rheumatoid arthritis (48-72%), with a wide variety of suspected diseases, including lupus. CONCLUSION: Patient and physician real-world surveys show that MPS I is under-recognized and diagnosis of MPS I remains delayed, particularly in patients with attenuated disease. Across regions and specialties, physicians require differential diagnosis education in order to improve early detection and early treatment initiation of MPS I.

Recommendations for initiation and cessation of enzyme replacement therapy in patients with Fabry disease: the European Fabry Working Group consensus document.

INTRODUCTION: Fabry disease (FD) is a lysosomal storage disorder resulting in progressive nervous system, kidney and heart disease. Enzyme replacement therapy (ERT) may halt or attenuate disease progression. Since administration is burdensome and expensive, appropriate use is mandatory. We aimed to define European consensus recommendations for the initiation and cessation of ERT in patients with FD. METHODS: A Delphi procedure was conducted with an online survey (n = 28) and a meeting (n = 15). Patient organization representatives were present at the meeting to give their views. Recommendations were accepted with ≥75% agreement and no disagreement. RESULTS: For classically affected males, consensus was achieved that ERT is recommended as soon as there are early clinical signs of kidney, heart or brain involvement, but may be considered in patients of ≥16 years in the absence of clinical signs or symptoms of organ involvement. Classically affected females and males with non-classical FD should be treated as soon as there are early clinical signs of kidney, heart or brain involvement, while treatment may be considered in females with non-classical FD with early clinical signs that are considered to be due to FD. Consensus was achieved that treatment should not be withheld from patients with severe renal insufficiency (GFR < 45 ml/min/1.73 m(2)) and from those on dialysis or with cognitive decline, but carefully considered on an individual basis. Stopping ERT may be considered in patients with end stage FD or other co-morbidities, leading to a life expectancy of <1 year. In those with cognitive decline of any cause, or lack of response for 1 year when the sole indication for ERT is neuropathic pain, stopping ERT may be considered. Also, in patients with end stage renal disease, without an option for renal transplantation, in combination with advanced heart failure (NYHA class IV), cessation of ERT should be considered. ERT in patients who are non-compliant or fail to attend regularly at visits should be stopped. CONCLUSION: The recommendations can be used as a benchmark for initiation and cessation of ERT, although final decisions should be made on an individual basis. Future collaborative efforts are needed for optimization of these recommendations.

Mortality in patients with morquio syndrome a.

BACKGROUND: Morquio syndrome A (mucopolysaccharidosis type IVA) is an autosomal recessive, life-limiting lysosomal storage disease characterized by deficient activity of the enzyme galactosamine-6-sulfatase. The disease affects multiple body systems, and patients require multidisciplinary care from an early age. METHODS: To better understand the natural progression of the disease, life expectancy and common causes of death, death certificates were evaluated for 27 patients (15 male, 12 female) with Morquio syndrome A in the UK, covering the years 1975-2010. RESULTS: Mean age at death (±standard deviation) was 25.30 ± 17.43 years, with female patients living longer than male patients (26.55 ± 12.28 years versus 22.95 ± 17.63 years, respectively). Respiratory failure was the primary cause of death in nearly two-thirds of patients (63%). Other causes of death were cardiac failure (11%), post-traumatic organ failure (11%), complications of surgery (11%) and myocardial infarction (4%). Life expectancy increased gradually over time (R (2) = 0.0963), and mean age at death due to respiratory failure improved from 17.42 ± 9.54 years in the 1980s to 30.74 ± 10.84 years in the 2000s. CONCLUSIONS: The current data suggest that survival of patients with Morquio syndrome A in the UK has improved in recent decades. It is possible that improvements in multidisciplinary care and referral of patients to specialist centres underlie this trend. It is hoped that novel disease-specific treatments such as enzyme replacement therapy and haematopoietic stem cell therapy will help to extend the lifespan of patients with Morquio syndrome further still.

Burden of disease in patients with Morquio A syndrome: results from an international patient-reported outcomes survey.

BACKGROUND: Morquio A syndrome (or mucopolysaccharidosis IVa) is an ultra-rare multi-organ disease, resulting in significantly impaired functional capacity, mobility and quality of life (QoL). METHODS: This patient-reported outcomes survey evaluated the global burden of Morquio A among adults (≥18 years, N = 27) and children (7-17 years, N = 36), including the impact on mobility, QoL, pain and fatigue. QoL was assessed using the general Health-Related Quality of Life (HRQoL) questionnaire (the EuroQol [EQ]-5D-5L). Pain and pain interference with daily activities were assessed using the Brief Pain Inventory Short Form (BPI-SF) in adults and the Adolescent Pediatric Pain Tool (APPT) in children. Fatigue was assessed by questioning the patients on the number of evenings in a week they felt extremely tired. RESULTS: The clinical data showed a wide heterogeneity in clinical manifestations between patients, with the majority of patients showing differing levels of endurance, short stature, bone and joint abnormalities, abnormal gait and eye problems. Mobility was considerably impaired: 44.4% of children and 85.2% of adult patients were using a wheelchair. High wheelchair reliance significantly reduced QoL. This was mainly driven by reduced scores in the Mobility, Self-care, and Usual Activity domains. The HRQoL utility values were 0.846, 0.582 and 0.057 respectively in adults not using a wheelchair, using a wheelchair only when needed and always using a wheelchair; values were 0.534, 0.664 and -0.180 respectively in children. Employed adult patients had a better HRQoL than unemployed patients (HRQoL utility value 0.640 vs. 0.275, respectively).64% of children and 74% of adult patients had joint pain; fatigue was reported by 69% of children and 63% of adults. Overall, increased mobility was associated with more severe and widespread pain and more fatigue. CONCLUSIONS: The HRQoL of Morquio A patients is mainly driven by the ability to remain independently mobile without becoming wheelchair dependent. Their QoL reduces dramatically if they always have to use their wheelchair. Even a slightly better mobility (wheelchair use only when needed) greatly improves QoL. Maintenance of functional capacity and mobility paired with better pain management are likely to improve QoL.

Mucopolysaccharidosis type II: European recommendations for the diagnosis and multidisciplinary management of a rare disease.

UNLABELLED: Mucopolysaccharidosis type II (MPS II) is a rare, life-limiting, X-linked recessive disease characterised by deficiency of the lysosomal enzyme iduronate-2-sulfatase. Consequent accumulation of glycosaminoglycans leads to pathological changes in multiple body systems. Age at onset, signs and symptoms, and disease progression are heterogeneous, and patients may present with many different manifestations to a wide range of specialists. Expertise in diagnosing and managing MPS II varies widely between countries, and substantial delays between disease onset and diagnosis can occur. In recent years, disease-specific treatments such as enzyme replacement therapy and stem cell transplantation have helped to address the underlying enzyme deficiency in patients with MPS II. However, the multisystem nature of this disorder and the irreversibility of some manifestations mean that most patients require substantial medical support from many different specialists, even if they are receiving treatment. This article presents an overview of how to recognise, diagnose, and care for patients with MPS II. Particular focus is given to the multidisciplinary nature of patient management, which requires input from paediatricians, specialist nurses, otorhinolaryngologists, orthopaedic surgeons, ophthalmologists, cardiologists, pneumologists, anaesthesiologists, neurologists, physiotherapists, occupational therapists, speech therapists, psychologists, social workers, homecare companies and patient societies. TAKE-HOME MESSAGE: Expertise in recognising and treating patients with MPS II varies widely between countries. This article presents pan-European recommendations for the diagnosis and management of this life-limiting disease.

The prevalence of and survival in Mucopolysaccharidosis I: Hurler, Hurler-Scheie and Scheie syndromes in the UK.

BACKGROUND: Mucopolysaccharidosis type I (MPS I) is a rare lysosomal storage disease subdivided into three phenotypes of increasing severity: Scheie, Hurler-Scheie and Hurler. To gauge the effectiveness of treatments and to determine the load likely to fall on health-care systems, it is necessary to understand the prevalence and natural progression of the disease especially with regard to life-expectancy. In general such data on the natural history of lysosomal storage diseases is sparse. METHODS: Analysis of prevalence and patient survival in MPS I disease using a unique longitudinal data set initiated and maintained over a period of more than 20 years by the Society for Mucopolysaccharide Diseases (UK). RESULTS: The birth prevalence of MPS I in England and Wales over the period 1981 to 2003 was 1.07/100,000 births and within +/- 5% of estimates reported in several studies that examined reasonably large populations. The median survival for MPS I patients (including all phenotypes irrespective of various treatments) was found by Kaplan-Meier analysis to be 11.6 years. This result was driven by the relatively poor survival of patients with the Hurler phenotype who, irrespective of any treatments received, had a median survival of 8.7 years; when censoring for receipt of bone marrow transplant (BMT) was implemented median survival of Hurler patients was diminished to 6.8 years. The difference between these survival curves was statistically significant by log rank test and can be attributed to beneficial effects of BMT and or selection of patients with superior prognosis for intervention with BMT. Survival curves for Hurler patients who received and did not receive BMT were very different. Probability of survival at 2 year after BMT was ~68% and was similar to this after 5 years (66%) and ten years (64%); the mean age of Hurler patients at receipt of BMT was 1.33 years (range 0.1 to 3 years). Follow up was insufficient to determine median survival of the milder phenotypes however, unsurprisingly, this was clearly superior to that for Hurler patients. CONCLUSION: The birth prevalence of MPS I in England and Wales is 1.07/100,000 and the median survival for MPS I patients is 11.6 years.