Recent insights into peroxisome biogenesis and associated diseases.

Peroxisomes are single-membrane organelles present in eukaryotes. The functional importance of peroxisomes in humans is represented by peroxisome-deficient peroxisome biogenesis disorders (PBDs), including Zellweger syndrome. Defects in the genes that encode the 14 peroxins that are required for peroxisomal membrane assembly, matrix protein import and division have been identified in PBDs. A number of recent findings have advanced our understanding of the biology, physiology and consequences of functional defects in peroxisomes. In this Review, we discuss a cooperative cell defense mechanisms against oxidative stress that involves the localization of BAK (also known as BAK1) to peroxisomes, which alters peroxisomal membrane permeability, resulting in the export of catalase, a peroxisomal enzyme. Another important recent finding is the discovery of a nucleoside diphosphate kinase-like protein that has been shown to be essential for how the energy GTP is generated and provided for the fission of peroxisomes. With regard to PBDs, we newly identified a mild mutation, Pex26-F51L that causes only hearing loss. We will also discuss findings from a new PBD model mouse defective in Pex14, which manifested dysregulation of the BDNF-TrkB pathway, an essential signaling pathway in cerebellar morphogenesis. Here, we thus aim to provide a current view of peroxisome biogenesis and the molecular pathogenesis of PBDs.

Novel REEP6 gene mutation associated with autosomal recessive retinitis pigmentosa.

PURPOSE: This study reports the ophthalmic and genetic findings of a Cameroonian patient with autosomal recessive retinitis pigmentosa (arRP) caused by a novel Receptor Expression Enhancing Protein 6 (REEP6) homozygous mutation. PATIENT AND METHODS: A 33-year-old man underwent comprehensive ophthalmic examinations, including visual acuity measurements, dilated fundus imaging, electroretinography (ERG), and spectral-domain optical coherence tomography (SD-OCT). Short-wavelength fundus autofluorescence (SW-AF) and near-infrared fundus autofluorescence (NIR-AF) were also evaluated. Whole exome sequencing (WES) was used to identify potential pathogenic variants. RESULTS: Fundus examination revealed typical RP findings with additional temporal ten micron yellow dots. SD-OCT imaging revealed cystoid macular edema and perifoveal outer retinal atrophy with centrally preserved inner segment ellipsoid zone (EZ) bands. Hyperreflective spots were seen in the inner retinal layers. On SW-AF images, a hypoautofluorescent area in the perifoveal area was observed. NIR-AF imaging revealed an irregularly shaped hyperautofluorescent ring. His visual acuity was mildly affected. ERG showed undetectable rod responses and intact cone responses. Genetic testing via WES revealed a novel homozygous mutation (c.295G>A, p.Glu99Lys) in the gene encoding REEP6, which is predicted to alter the charge in the transmembrane helix. CONCLUSIONS: This report is not only the first description of a Cameroonian patient with arRP associated with a REEP6 mutation, but also this particular genetic alteration. Substitution of p.Glu99Lys in REEP6 likely disrupts the interactions between REEP6 and the ER membrane. NIR-AF imaging may be particularly useful for assessing functional photoreceptor cells and show an "avocado" pattern of hyperautofluorescence in patients with the REEP6 mutation.

Mutations in SPATA5 Are Associated with Microcephaly, Intellectual Disability, Seizures, and Hearing Loss.

Using whole-exome sequencing, we have identified in ten families 14 individuals with microcephaly, developmental delay, intellectual disability, hypotonia, spasticity, seizures, sensorineural hearing loss, cortical visual impairment, and rare autosomal-recessive predicted pathogenic variants in spermatogenesis-associated protein 5 (SPATA5). SPATA5 encodes a ubiquitously expressed member of the ATPase associated with diverse activities (AAA) protein family and is involved in mitochondrial morphogenesis during early spermatogenesis. It might also play a role in post-translational modification during cell differentiation in neuronal development. Mutations in SPATA5 might affect brain development and function, resulting in microcephaly, developmental delay, and intellectual disability.

Clinical course of sly syndrome (mucopolysaccharidosis type VII).

BACKGROUND: Mucopolysaccharidosis VII (MPS VII) is an ultra-rare disease characterised by the deficiency of ß-glucuronidase (GUS). Patients' phenotypes vary from severe forms with hydrops fetalis, skeletal dysplasia and mental retardation to milder forms with fewer manifestations and mild skeletal abnormalities. Accurate assessments on the frequency and clinical characteristics of the disease have been scarce. The aim of this study was to collect such data. METHODS: We have conducted a survey of physicians to document the medical history of patients with MPS VII. The survey included anonymous information on patient demographics, family history, mode of diagnosis, age of onset, signs and symptoms, severity, management, clinical features and natural progression of the disease. RESULTS: We collected information on 56 patients from 11 countries. Patients with MPS VII were classified based on their phenotype into three different groups: (1) neonatal non-immune hydrops fetalis (NIHF) (n=10), (2) Infantile or adolescent form with history of hydrops fetalis (n=13) and (3) Infantile or adolescent form without known hydrops fetalis (n=33). Thirteen patients with MPS VII who had the infantile form with history of hydrops fetalis and survived childhood, had a wide range of clinical manifestations from mild to severe. Five patients underwent bone marrow transplantation and one patient underwent enzyme replacement therapy with recombinant human GUS. CONCLUSIONS: MPS VII is a pan-ethnic inherited lysosomal storage disease with considerable phenotypical heterogeneity. Most patients have short stature, skeletal dysplasia, hepatosplenomegaly, hernias, cardiac involvement, pulmonary insufficiency and cognitive impairment. In these respects it resembles MPS I and MPS II. In MPS VII, however, one unique and distinguishing clinical feature is the unexpectedly high proportion of patients (41%) that had a history of NIHF. Presence of NIHF does not, by itself, predict the eventual severity of the clinical course, if the patient survives infancy.

A multicenter, open-label extension study of velaglucerase alfa in Japanese patients with Gaucher disease: Results after a cumulative treatment period of 24months.

Enzyme replacement therapy (ERT) with exogenous glucocerebrosidase is indicated to treat symptomatic Gaucher disease (GD), a rare, inherited metabolic disorder. ERT with velaglucerase alfa, which is produced in a human cell line using gene activation technology, was studied in a 12-month phase III trial in Japanese patients with type 1 or 3 GD who were switched from imiglucerase ERT (n=6); the current, open-label, 12-month extension study was designed to assess longer-term safety and efficacy. Two adult and three pediatric patients (aged <18years) were enrolled into the extension study. Every-other-week intravenous infusions were administered for 63-78weeks at average doses between 51.5 and 60.7units/kg. Three non-serious adverse events were considered related to velaglucerase alfa treatment, but no patient discontinued from the study. Six serious but non-drug-related adverse events were reported. No patient tested positive for anti-velaglucerase alfa antibodies. Hemoglobin concentrations, platelet counts, and liver and spleen volumes (normalized to body weight) in these patients were generally stable over a cumulative 24-month period from the baseline of the parent trial. The data suggest that velaglucerase alfa was well tolerated and maintained clinical stability in Japanese GD patients over 2years after switching from imiglucerase. ClinicalTrials.gov identifier NCT01842841.

Hematopoietic stem cell transplantation for Morquio A syndrome.

Morquio A syndrome features systemic skeletal dysplasia. To date, there has been no curative therapy for this skeletal dysplasia. No systemic report on a long-term effect of hematopoietic stem cell transplantation (HSCT) for Morquio A has been described. We conducted HSCT for 4 cases with Morquio A (age at HSCT: 4-15years, mean 10.5years) and followed them at least 10years (range 11-28years; mean 19years). Current age ranged between 25 and 36years of age (mean 29.5years). All cases had a successful full engraftment of allogeneic bone marrow transplantation without serious GVHD. Transplanted bone marrow derived from HLA-identical siblings (three cases) or HLA-identical unrelated donor. The levels of the enzyme activity in the recipient's lymphocytes reached the levels of donors' enzyme activities within two years after HSCT. For the successive over 10years post-BMT, GALNS activity in lymphocytes was maintained at the same level as the donors. Except one case who had osteotomy in both legs one year later post BMT, other three cases had no orthopedic surgical intervention. All cases remained ambulatory, and three of them could walk over 400m. Activity of daily living (ADL) in patients with HSCT was better than untreated patients. The patient who underwent HSCT at four years of age showed the best ADL score. In conclusion, the long-term study of HSCT has demonstrated therapeutic effect in amelioration of progression of the disease in respiratory function, ADL, and biochemical findings, suggesting that HSCT is a therapeutic option for patients with Morquio A.

Activity of daily living for Morquio A syndrome.

The aim of this study was to evaluate the activity of daily living (ADL) and surgical interventions in patients with mucopolysaccharidosis IVA (MPS IVA). The factor(s) that affect ADL are age, clinical phenotypes, surgical interventions, therapeutic effect, and body mass index. The ADL questionnaire comprises three domains: "Movement," "Movement with cognition," and "Cognition." Each domain has four subcategories rated on a 5-point scale based on the level of assistance. The questionnaire was collected from 145 healthy controls and 82 patients with MPS IVA. The patient cohort consisted of 63 severe and 17 attenuated phenotypes (2 were undefined); 4 patients treated with hematopoietic stem cell transplantation (HSCT), 33 patients treated with enzyme replacement therapy (ERT) for more than a year, and 45 untreated patients. MPS IVA patients show a decline in ADL scores after 10years of age. Patients with a severe phenotype have a lower ADL score than healthy control subjects, and lower scores than patients with an attenuated phenotype in domains of "Movement" and "Movement with cognition." Patients, who underwent HSCT and were followed up for over 10years, had higher ADL scores and fewer surgical interventions than untreated patients. ADL scores for ERT patients (2.5years follow-up on average) were similar with the-age-matched controls below 10years of age, but declined in older patients. Surgical frequency was higher for severe phenotypic patients than attenuated ones. Surgical frequency for patients treated with ERT was not decreased compared to untreated patients. In conclusion, we have shown the utility of the proposed ADL questionnaire and frequency of surgical interventions in patients with MPS IVA to evaluate the clinical severity and therapeutic efficacy compared with age-matched controls.

Human embryos commonly form abnormal nuclei during development: a mechanism of DNA damage, embryonic aneuploidy, and developmental arrest.

STUDY QUESTION: What is the prevalence and developmental significance of morphologic nuclear abnormalities in human preimplantation embryos? SUMMARY ANSWER: Nuclear abnormalities are commonly found in human IVF embryos and are associated with DNA damage, aneuploidy, and decreased developmental potential. WHAT IS KNOWN ALREADY: Early human embryonic development is complicated by genomic errors that occur after fertilization. The appearance of extra-nuclear DNA, which has been observed in IVF, may be a result of such errors. However, the mechanism by which abnormal nuclei form and the impact on DNA integrity and embryonic development is not understood. STUDY DESIGN, SIZE, DURATION: Cryopreserved human cleavage-stage embryos (n = 150) and cryopreserved blastocysts (n = 105) from clinical IVF cycles performed between 1997 and 2008 were donated for research. Fresh embryos (n = 60) of poor quality that were slated for discard were also used. Immunohistochemical, microscopic and cytogenetic analyses at different developmental stages and morphologic grades were performed. PARTICIPANTS/MATERIALS, SETTING, METHODS: Embryos were fixed and stained for DNA, centromeres, mitotic activity and DNA damage and imaged using confocal microscopy. Rates of abnormal nuclear formation were compared between morphologically normal cleavage-stage embryos, morphologically normal blastocysts, and poor quality embryos. To control for clinical and IVF history of oocytes donors, and quality of frozen embryos within our sample, cleavage-stage embryos (n = 52) were thawed and fixed at different stages of development and then analyzed microscopically. Cleavage-stage embryos (n = 9) were thawed and all blastomeres (n = 62) were disaggregated, imaged and analyzed for karyotype. Correlations were made between microscopic and cytogenetic findings of individual blastomeres and whole embryos. MAIN RESULTS AND THE ROLE OF CHANCE: The frequency of microscopic nuclear abnormalities was lower in blastocysts (5%; 177/3737 cells) than in cleavage-stage embryos (16%, 103/640 blastomeres, P < 0.05) and highest in arrested embryos (65%; 44/68 blastomeres, P < 0.05). DNA damage was significantly higher in cells with microscopic nuclear abnormalities (γH2AX (phosphorylated (Ser139) histone H2A.X): 87.1%, 74/85; replication protein A: 72.9%, 62/85) relative to cells with normal nuclear morphology (γH2AX: 9.3%, 60/642; RPA: 5.6%, 36/642) (P < 0.05). Blastomeres containing nuclear abnormalities were strongly associated with aneuploidy (Fisher exact test, two-tailed, P < 0.01). LIMITATIONS, REASONS FOR CAUTION: The embryos used were de-identified, and the clinical and IVF history was unknown. WIDER IMPLICATIONS OF THE FINDINGS: This study explores a mechanism of abnormal embryonic development post-fertilization. While most of the current data have explored abnormal meiotic chromosome segregation in oocytes as a primary mechanism of reproductive failure, abnormal nuclear formation during early mitotic cell division in IVF embryos also plays a significant role. The detection of abnormal nuclear formation may have clinical application in noninvasive embryo selection during IVF. STUDY FUNDING/COMPETING INTERESTS: The study was supported by Columbia University and the New York Stem Cell Foundation. Authors declare no competing interest.

Hematopoietic stem cell transplantation for inborn errors of metabolism: A report from the Research Committee on Transplantation for Inborn Errors of Metabolism of the Japanese Ministry of Health, Labour and Welfare and the Working Group of the Japan Society for Hematopoietic Cell Transplantation.

A total of 216 patients with IEM were treated by allogeneic HSCT in Japan from 1985 until 2010. The results of UCBT have improved, and the OS rate of UCBT (81.9%) was not different from those of RBMT (87.2%) or UBMT (73.9%) in 2000-2010. However, EFS rates in RBMT (73.2%) and UBMT (62.2%) were better than that in UCBT (49.5%), and the difference between RBMT and UCBT was significant (p = 0.01). The EFS rate of patients conditioned by RIC (74.6%) was comparable or slightly better than in those who underwent MAC with irradiation (57.9%) or without irradiation (54.2%) in 2000-2010. A more pronounced trend was observed toward differential EFS for UCBT in 2000-2010: RIC (62.9%), MAC with irradiation (20.0%), and MAC without irradiation (42.1%). The difference between RIC and MAC with irradiation was significant (p < 0.03). In summary, we report a Japanese registry analysis of HSCT for IEM with improving survival in UCBT. The introduction of RIC after 2000 was considered to contribute to this improvement. UCBT could be recommended for those who lack an HLA-identical sibling donor.

Activities of daily living in patients with Hunter syndrome: impact of enzyme replacement therapy and hematopoietic stem cell transplantation.

The aim of this study was to assess the activities of daily living (ADL) in patients with Hunter syndrome (mucopolysaccharidosis II; MPS II) using a newly designed ADL questionnaire. We applied the questionnaire to evaluate clinical phenotypes and therapeutic efficacies of enzyme replacement therapy (ERT) and hematopoietic stem cell transplantation (HSCT). We also explored early signs and symptoms to make early diagnosis feasible. We devised a new ADL questionnaire with three domains: "movement," "movement with cognition," and "cognition." Each domain has four subcategories rated on a 5-point scale based on level of assistance. We also scored signs and symptoms unique to MPS by 12 subcategories (five points per category), providing 60 points in total. The questionnaire was first administered to 138 healthy Japanese controls (0.33-50 years), and successively, to 74 Japanese patients with Hunter syndrome (4-49 years). The patient cohort consisted of 51 severe and 23 attenuated phenotypes; 20 patients treated with HSCT, 23 patients treated early with ERT (≤8 years), 25 patients treated late with ERT (>8 years), and 4 untreated patients. Among 18 severe phenotypic patients treated by HSCT, 10 were designated as early HSCT (≤5years), while 8 were designated as late HSCT (>5years). Scores from patients with severe phenotypes were lower than controls and attenuated phenotypes in all categories. Among patients with severe phenotypes, there was a trend that HSCT provides a higher ADL score than early ERT, and there was a significant difference in ADL scores between late ERT and HSCT groups. Early ERT and early HSCT provided a higher score than late ERT and late HSCT, respectively. In conclusion, we have evaluated the feasibility of a new questionnaire in control population and patients with Hunter syndrome, leading to a novel evaluation method for clinical phenotypes and therapeutic efficacy. Early treatment with HSCT provides a better consequence in ADL of patients.

Identifying the need for a multidisciplinary approach for early recognition of mucopolysaccharidosis VI (MPS VI).

Mucopolysaccharidosis VI (MPS VI, Maroteaux-Lamy syndrome) is caused by deficient activity of the enzyme, N-acetylgalactosamine-4-sulfatase, resulting in impaired degradation of the glycosaminoglycan dermatan sulfate. Patients experience a range of manifestations including joint contractures, short stature, dysostosis multiplex, coarse facial features, decreased pulmonary function, cardiac abnormalities, corneal clouding and shortened life span. Recently, clinicians from institutions in the Asia-Pacific region met to discuss the occurrence and implications of delayed diagnosis and misdiagnosis of MPS VI in the patients they have managed. Eighteen patients (44% female) were diagnosed. The most common sign presented by the patients was bone deformities in 11 patients (65%). Delays to diagnosis occurred due to the lack of or distance to diagnostic facilities for four patients (31%), alternative diagnoses for two patients (15%), and misleading symptoms experienced by two patients (15%). Several patients experienced manifestations that were subtler than would be expected and were subsequently overlooked. Several cases highlighted the unique challenges associated with diagnosing MPS VI from the perspective of different specialties and provide insights into how these patients initially present, which may help to elucidate strategies to improve the diagnosis of MPS VI.

Therapies for the bone in mucopolysaccharidoses.

Patients with mucopolysaccharidoses (MPS) have accumulation of glycosaminoglycans in multiple tissues which may cause coarse facial features, mental retardation, recurrent ear and nose infections, inguinal and umbilical hernias, hepatosplenomegaly, and skeletal deformities. Clinical features related to bone lesions may include marked short stature, cervical stenosis, pectus carinatum, small lungs, joint rigidity (but laxity for MPS IV), kyphoscoliosis, lumbar gibbus, and genu valgum. Patients with MPS are often wheelchair-bound and physical handicaps increase with age as a result of progressive skeletal dysplasia, abnormal joint mobility, and osteoarthritis, leading to 1) stenosis of the upper cervical region, 2) restrictive small lung, 3) hip dysplasia, 4) restriction of joint movement, and 5) surgical complications. Patients often need multiple orthopedic procedures including cervical decompression and fusion, carpal tunnel release, hip reconstruction and replacement, and femoral or tibial osteotomy through their lifetime. Current measures to intervene in bone disease progression are not perfect and palliative, and improved therapies are urgently required. Enzyme replacement therapy (ERT), hematopoietic stem cell transplantation (HSCT), and gene therapy are available or in development for some types of MPS. Delivery of sufficient enzyme to bone, especially avascular cartilage, to prevent or ameliorate the devastating skeletal dysplasias remains an unmet challenge. The use of an anti-inflammatory drug is also under clinical study. Therapies should start at a very early stage prior to irreversible bone lesion, and damage since the severity of skeletal dysplasia is associated with level of activity during daily life. This review illustrates a current overview of therapies and their impact for bone lesions in MPS including ERT, HSCT, gene therapy, and anti-inflammatory drugs.

Consequence of climate mitigation on the risk of hunger.

Climate change and mitigation measures have three major impacts on food consumption and the risk of hunger: (1) changes in crop yields caused by climate change; (2) competition for land between food crops and energy crops driven by the use of bioenergy; and (3) costs associated with mitigation measures taken to meet an emissions reduction target that keeps the global average temperature increase to 2 °C. In this study, we combined a global computable general equilibrium model and a crop model (M-GAEZ), and we quantified the three impacts on risk of hunger through 2050 based on the uncertainty range associated with 12 climate models and one economic and demographic scenario. The strong mitigation measures aimed at attaining the 2 °C target reduce the negative effects of climate change on yields but have large negative impacts on the risk of hunger due to mitigation costs in the low-income countries. We also found that in a strongly carbon-constrained world, the change in food consumption resulting from mitigation measures depends more strongly on the change in incomes than the change in food prices.

Successful management of pregnancy with very-long-chain acyl-coenzyme A dehydrogenase deficiency.

Very-long-chain acyl-coenzyme A dehydrogenase deficiency (VLCADD) is a rare and life-threatening disease characterized by an enzymatic defect in the fatty acid ß-oxidation pathway. A nulliparous woman with VLCADD showed improvements in serum levels of the long-chain acylcarnitine moiety (C14:1) during pregnancy and successfully delivered a healthy infant vaginally. Pregnancy and vaginal delivery can be successfully completed in patients with VLCADD with careful management.

Climate change impact and adaptation assessment on food consumption utilizing a new scenario framework.

We assessed the impacts of climate change and agricultural autonomous adaptation measures (changes in crop variety and planting dates) on food consumption and risk of hunger considering uncertainties in socioeconomic and climate conditions by using a new scenario framework. We combined a global computable general equilibrium model and a crop model (M-GAEZ), and estimated the impacts through 2050 based on future assumptions of socioeconomic and climate conditions. We used three Shared Socioeconomic Pathways as future population and gross domestic products, four Representative Concentration Pathways as a greenhouse gas emissions constraint, and eight General Circulation Models to estimate climate conditions. We found that (i) the adaptation measures are expected to significantly lower the risk of hunger resulting from climate change under various socioeconomic and climate conditions. (ii) population and economic development had a greater impact than climate conditions for risk of hunger at least throughout 2050, but climate change was projected to have notable impacts, even in the strong emission mitigation scenarios. (iii) The impact on hunger risk varied across regions because levels of calorie intake, climate change impacts and land scarcity varied by region.

Tidal volume and airway pressure under percutaneous transtracheal ventilation without a jet ventilator: comparison of high-flow oxygen ventilation and manual ventilation in complete and incomplete upper airway obstruction models.

PURPOSE: Percutaneous transtracheal ventilation (PTV) can be life-saving in a cannot ventilate, cannot intubate situation. The aim of this study was to investigate the efficacy of PTV by measuring tidal volumes (VTs) and airway pressure (Paw) in high-flow oxygen ventilation and manual ventilation using a model lung. METHODS: We examined 14G, 16G, 18G, and 20G intravenous catheters and minitracheotomy catheters. In high-flow oxygen ventilation, the flow was set to 10 L/min, while the inspiratory:expiratory phases (I:E) were 1 s:4 s in the complete upper airway obstruction model and 1 s:1 s in the incomplete obstruction model. In manual ventilation, I:E were 2 s:4 s in the complete obstruction model and 2 s:3 s in the incomplete obstruction model. We ventilated through each catheter for 2 min and measured VT and Paw. RESULTS: In high-flow ventilation, the average VTs were approximately 150 ml and <100 ml with 14G catheters in complete and incomplete upper airway obstruction, respectively. The VTs obtained were reduced when the bore size was decreased. In manual ventilation, the average VTs were over 300 ml and approximately 260 ml with 14G catheters in complete and incomplete upper airway obstruction, respectively. In high-flow ventilation, the airway pressure tended to be higher. The minitracheotomy catheters produced over 800 ml of VT and created almost no positive end-expiratory pressure. CONCLUSIONS: High-flow ventilation tends to result in higher airway pressure despite a smaller VT, which is probably due to a PEEP effect caused by high flow.

Organ size is limited by the number of embryonic progenitor cells in the pancreas but not the liver.

The determinants of vertebrate organ size are poorly understood, but the process is thought to depend heavily on growth factors and other environmental cues. In the blood and central nervous system, for example, organ mass is determined primarily by growth-factor-regulated cell proliferation and apoptosis to achieve a final target size. Here, we report that the size of the mouse pancreas is constrained by an intrinsic programme established early in development, one that is essentially not subject to growth compensation. Specifically, final pancreas size is limited by the size of the progenitor cell pool that is set aside in the developing pancreatic bud. By contrast, the size of the liver is not constrained by reductions in the progenitor cell pool. These findings show that progenitor cell number, independently of regulation by growth factors, can be a key determinant of organ size.

Molecular Genetic Testing Approaches for Retinitis Pigmentosa.

Retinitis pigmentosa (RP) affects approximately 1 in 4000 individuals. It has many different genetic etiologies and therefore diagnosis can be challenging. Understanding the different testing methodologies is beneficial for clinicians and researchers in order to select the best testing method, whether it be panel testing, whole exome sequencing, or whole genome sequencing for individuals affected with RP. The Methods section also outlines the steps required to complete a WES assay, which has become a popular method for identifying the molecular diagnosis for individuals with RP.

Current diagnosis and management of mucopolysaccharidosis VI in the Asia-Pacific region.

INTRODUCTION: Mucopolysaccharidosis (MPS) type VI (Maroteaux-Lamy syndrome) is a clinically heterogeneous lysosomal storage disorder. It presents significant diagnostic and treatment challenges due to the rarity of the disease and complexity of the phenotype. As information about MPS VI in Asia-Pacific countries is limited, a survey was conducted to assess current practices for diagnosis and management of MPS VI in this region. The participants were selected based on their experience in diagnosing and managing MPS patients. METHODS: The survey comprised 29 structured quantitative or qualitative questions. Follow-up consultations were undertaken to discuss the data further. RESULTS: Thirteen physicians from eight countries or regions (Australia, China, Hong Kong, Japan, Malaysia, Philippines, Taiwan and Thailand) were surveyed. At the time of the survey twenty-two patients with MPS VI were directly treated by the respondents and most (~80%) had rapidly progressing disease. A wide range of medical specialists are involved in managing patients with MPS VI, the most common being orthopedic surgeons, pediatricians and geneticists. The availability/accessibility of diagnostic tools, therapies and national insurance coverage vary greatly across the countries/regions and, in some cases, between different regions within the same country. Currently, there are national MPS management groups in Australia and Japan. Australia, Taiwan and Hong Kong have local guidelines for managing MPS and local MPS registries are available in Australia, Taiwan, and Japan. CONCLUSIONS: This survey highlights differences in the diagnosis and management of MPS VI between Asia-Pacific countries/regions. Important barriers to advancing the identification, understanding and treatment of MPS VI include the paucity of epidemiological information, limited access to laboratory diagnostics and therapies, low disease awareness, and a lack of monitoring and treatment guidelines. There is a clear need to facilitate communications between physicians and establish regional or national disease registries, a multidisciplinary referral network, and a centralized diagnostic and management framework.

Long-term efficacy of hematopoietic stem cell transplantation on brain involvement in patients with mucopolysaccharidosis type II: a nationwide survey in Japan.

Hematopoietic stem cell transplantation (HSCT) has not been indicated for patients with mucopolysaccharidosis II (MPS II, Hunter syndrome), while it is indicated for mucopolysaccharidosis I (MPS I) patients <2 years of age and an intelligence quotient (IQ) of ≥ 70. Even after the approval of enzyme replacement therapy for both of MPS I and II, HSCT is still indicated for patients with MPS I severe form (Hurler syndrome). To evaluate the efficacy and benefit of HSCT in MPS II patients, we carried out a nationwide retrospective study in Japan. Activities of daily living (ADL), IQ, brain magnetic resonance image (MRI) lesions, cardiac valvular regurgitation, and urinary glycosaminoglycan (GAG) were analyzed at baseline and at the most recent visit. We also performed a questionnaire analysis about ADL for an HSCT-treated cohort and an untreated cohort (natural history). Records of 21 patients were collected from eight hospitals. The follow-up period in the retrospective study was 9.6 ± 3.5 years. ADL was maintained around baseline levels. Cribriform changes and ventricular dilatation on brain MRI were improved in 9/17 and 4/17 patients, respectively. Stabilization of brain atrophy was shown in 11/17 patients. Cardiac valvular regurgitation was diminished in 20/63 valves. Urinary GAG concentration was remarkably lower in HSCT-treated patients than age-matched untreated patients. In the questionnaire analysis, speech deterioration was observed in 12/19 patients in the untreated cohort and 1/7 patient in HSCT-treated cohort. HSCT showed effectiveness towards brain or heart involvement, when performed before signs of brain atrophy or valvular regurgitation appear. We consider HSCT is worthwhile in early stages of the disease for patients with MPS II.