Prevalence of patients with lysosomal storage disorders and peroxisomal disorders: A nationwide survey in Japan.

INTRODUCTION: Lysosomal storage disorders and peroxisomal disorders are rare diseases caused by the accumulation of substrates of the metabolic pathway within lysosomes and peroxisomes, respectively. Owing to the rarity of these diseases, the prevalence of lysosomal storage disorders and peroxisomal disorders in Japan is unknown. Therefore, we conducted a nationwide survey to estimate the number of patients with lysosomal storage disorders and peroxisomal disorders in Japan. METHODS: A nationwide survey was conducted following the "Manual of nationwide epidemiological survey for understanding patient number and clinical epidemiology of rare diseases (3rd version)". A questionnaire asking for detailed information, such as disease phenotypes and medical history, was created and sent to 504 institutions with doctors who have experience in treating patients with lysosomal storage disorders and peroxisomal disorders. Result A total of 303 completed questionnaires were collected from 504 institutions (response rate: 60.1%). The number of patients was estimated by calculating the rate/frequency of overlap. The estimated number of patients was 1658 (±264.8) for Fabry disease, 72 (±11.3) for mucopolysaccharidosis I, 275 (±49.9) for mucopolysaccharidosis II, 211 (±31.3) for Gaucher disease, 124 (±25.8) for Pompe disease, 83 (±44.3) for metachromatic leukodystrophy, 57 (±9.4) for Niemann-Pick type C, and 262 (±42.3) for adrenoleukodystrophy. In addition the birth prevalence was calculated using the estimated number of patients and birth year data for each disease, and was 1.25 for Fabry disease, 0.09 for mucopolysaccharidosis I, 0.38 for mucopolysaccharidosis II, 0.19 for Gaucher disease, 0.14 for Pompe disease, 0.16 for metachromatic leukodystrophy, 0.16 for Niemann-Pick type C, and 0.20 for adrenoleukodystrophy. DISCUSSION: Among the diseases analyzed, the disease with the highest prevalence was Fabry disease, followed by mucopolysaccharidosis II, adrenoleukodystrophy, Gaucher disease and metachromatic leukodystrophy. In particular, the high prevalence of mucopolysaccharidosis II and Gaucher disease type II was a feature characteristic of Japan. CONCLUSION: We estimated the number of patients with lysosomal storage disorders and peroxisomal disorders in Japan. The details of the age at diagnosis and treatment methods for each disease were clarified, and will be useful for the early diagnosis of these patients and to provide appropriate treatments. Furthermore, our results suggest that supportive care and the development of an environment that can provide optimal medical care is important in the future.

SnapShot: Lysosomal Storage Diseases.

Lysosomal storage diseases (LSDs) represent a group of monogenic inherited metabolic disorders characterized by the progressive accumulation of undegraded substrates inside lysosomes, resulting in aberrant lysosomal activity and homeostasis. This SnapShot summarizes the intracellular localization and function of proteins implicated in LSDs. Common aspects of LSD pathogenesis and the major current therapeutic approaches are noted. To view this SnapShot, open or download the PDF.

Ophthalmic manifestations of Gaucher disease: the most common lysosomal storage disorder.

Gaucher disease (GD) results from a deficiency of glucocerebrosidase activity and the subsequent accumulation of the enzyme's metabolites, principally glucosylsphingosine and glucosylceramide. There are three principal forms: Type I, which is the most common, is usually considered non-neuronopathic. Type II, III and IIIc manifest earlier and have neurological sequelae due to markedly reduced enzyme activity. Gaucher's can be associated with ophthalmological sequelae but these have not been systematically reviewed. We therefore performed a comprehensive literature review of all such ophthalmic abnormalities associated with the different types of Gaucher disease. We systematically searched the literature (1950 - present) for functional and structural ocular abnormalities arising in patients with Gaucher disease and found that all subtypes can be associated with ophthalmic abnormalities; these range from recently described intraocular lesions to disease involving the adnexae, peripheral nerves and brain. In summary, Gaucher can affect most parts of the eye. Rarely is it sight-threatening; some but not all manifestations are amenable to treatment, including with enzyme replacement and substrate reduction therapy. Retinal involvement is rare but patients with ocular manifestations should be monitored and treated early to reduce the risk of progression and further complications. As Gaucher disease is also associated with Parkinsons disease and may also confer an increased risk of malignancy (particularly haematological forms and melanoma), any ocular abnormalities should be fully investigated to exclude these potential underlying conditions.

Lysosomal storage disorders: Morphologic appraisal in Indian population.

BACKGROUND: Lysosomal storage disorders (LSDs) comprise a group of at least 50 distinct genetic diseases, each one resulting from the deficiency of a particular lysosomal enzyme involved in metabolism. We attempt to study and further subclassify pediatric LSDs into Gaucher's and non-Gaucher's category based on the morphologic variables seen in the bone marrow aspiration smears and trephine biopsy sections. MATERIALS AND METHODS: Pediatric (<12 years age) cases of LSDs diagnosed by bone marrow aspiration and trephine biopsy specimens, in the last 12 years period, were retrieved. The archival material and the relevant clinical as well as hematologic parameters were reviewed. RESULTS: From January 1997 to December 2008, 55 cases were diagnosed as LSDs. Based on bone marrow morphology, 56% (n = 31) cases were diagnosed as non-Gaucher's and the remaining 44% (n = 24) cases as Gaucher's disease, the ratio being 1.29:1. Anemia and thrombocytopenia were more commonly observed in Gaucher's disease (91.67 and 62.5%) as compared to non-Gaucher's group (74.19 and 19.35%). Neurologic symptoms and signs were more frequently present in non-Gaucher's cases (45.16%) as compared to Gaucher's group (29.17%). CONCLUSION: LSDs can be classified into Gaucher's and non-Gaucher's subtypes based on the characteristic cytomorphology of the storage cells in Giemsa-stained bone marrow aspiration smears and on hematoxylin and eosin-stained trephine biopsy sections. This approach would be fairly adequate for therapeutic and prognostic purposes in resource.constrained settings, where enzyme studies and mutational analysis may not be easily available.

Pilot study of newborn screening for six lysosomal storage diseases using Tandem Mass Spectrometry.

BACKGROUND: There is current expansion of newborn screening (NBS) programs to include lysosomal storage disorders because of the availability of treatments that produce an optimal clinical outcome when started early in life. OBJECTIVE: To evaluate the performance of a multiplex-tandem mass spectrometry (MS/MS) enzymatic activity assay of 6 lysosomal enzymes in a NBS laboratory for the identification of newborns at risk for developing Pompe, Mucopolysaccharidosis-I (MPS-I), Fabry, Gaucher, Niemann Pick-A/B, and Krabbe diseases. METHODS AND RESULTS: Enzyme activities (acid α-glucosidase (GAA), galactocerebrosidase (GALC), glucocerebrosidase (GBA), α-galactosidase A (GLA), α-iduronidase (IDUA) and sphingomyeline phosphodiesterase-1 (SMPD-1)) were measured on ~43,000 de-identified dried blood spot (DBS) punches, and screen positive samples were submitted for DNA sequencing to obtain genotype confirmation of disease risk. The 6-plex assay was efficiently performed in the Washington state NBS laboratory by a single laboratory technician at the bench using a single MS/MS instrument. The number of screen positive samples per 100,000 newborns were as follows: GAA (4.5), IDUA (13.6), GLA (18.2), SMPD1 (11.4), GBA (6.8), and GALC (25.0). DISCUSSION: A 6-plex MS/MS assay for 6 lysosomal enzymes can be successfully performed in a NBS laboratory. The analytical ranges (enzyme-dependent assay response for the quality control HIGH sample divided by that for all enzyme-independent processes) for the 6-enzymes with the MS/MS is 5- to 15-fold higher than comparable fluorimetric assays using 4-methylumbelliferyl substrates. The rate of screen positive detection is consistently lower for the MS/MS assay compared to the fluorimetric assay using a digital microfluidics platform.

Demographic characteristics and distribution of lysosomal storage disorder subtypes in Eastern China.

Lysosomal storage disorders (LSDs) are a group of >50 different types of inherited metabolic disorders that result from defects in the lysosome. The aim of this study was to investigate the distribution and demographic characteristics of the different subtypes of LSDs in Eastern China. From 2006 to 2012, 376 out of 1331 clinically suspected patients were diagnosed with 17 different subtypes of LSDs at our hospital. Mucopolysaccharidoses (MPS) were the most common group of LSDs (50.5%), followed by sphingolipidoses (25.4%) and Pompe disease (19.8%). Mucolipidosis type II/III accounted for the remaining 4% of diagnosed LSDs. MPS II was the most common form of MPS, comprising 47.4% of all MPS cases diagnosed, followed by MPS IVA (26.8%) and MPS I (16.3%). Gaucher disease and Niemann-Pick disease type A/B were the two most common forms of sphingolipidoses. There was a large variation in the time between disease onset and eventual diagnosis, from 0.3 years in infantile-onset Pompe disease to 30 years in Fabry disease, highlighting timely and accurate diagnosis of LSDs as the main challenge in China.

Case definition and classification of leukodystrophies and leukoencephalopathies.

OBJECTIVE: An approved definition of the term leukodystrophy does not currently exist. The lack of a precise case definition hampers efforts to study the epidemiology and the relevance of genetic white matter disorders to public health. METHOD: Thirteen experts at multiple institutions participated in iterative consensus building surveys to achieve definition and classification of disorders as leukodystrophies using a modified Delphi approach. RESULTS: A case definition for the leukodystrophies was achieved, and a total of 30 disorders were classified under this definition. In addition, a separate set of disorders with heritable white matter abnormalities but not meeting criteria for leukodystrophy, due to presumed primary neuronal involvement and prominent systemic manifestations, was classified as genetic leukoencephalopathies (gLE). INTERPRETATION: A case definition of leukodystrophies and classification of heritable white matter disorders will permit more detailed epidemiologic studies of these disorders.

Las enfermedades de depósito lisosomal: ¿por qué los pacientes consultan al reumatólogo? / Lysosomal storage diseases: why do patients consult the rheumatologist?

The lysosomal storage diseases (LSD) are a group of approximately 50 hereditary diseases affecting the activity of several enzymes that degrade macromolecules within lysosomes. As consequence, incompletely degraded substrates are accumulated, causing cell damage and progressive multisystem diseases. Although they are considered part of the so called “rare diseases”, the LSD have become relevant since the availability for several of them of a specific treatment, through the periodic infusion of recombinant forms of the deficient enzymes. This enzyme replacement therapy can significantly improve the prognosis and the quality of life of patients. Several of the LSD affect the osteoarticular system, given symptoms that lead patients to consult first to the rheumatologist. The aim of this review is to highlight the clinical aspects of LSD, giving raise to the differential diagnosis with the rheumatic diseases...

Las enfermedades de depósito lisosomal (EDL) son un grupo de aproximadamente 50 patologías hereditarias que afectan la actividad de las enzimas que degradan diversas macromoléculas dentro de los lisosomas. Como consecuencia, se acumulan sustratos incompletamente degradados, produciendo daño celular y un cuadro clínico multisistémico y progresivo. Aunque se les considera parte de las llamadas “enfermedades raras”, las EDL han adquirido relevancia, pues desde hace pocos años es posible el tratamiento específico de varias de ellas a través de la infusión periódica de formas recombinantes de las enzimas deficientes, lo que puede mejorar significativamente el pronóstico vital y la calidad de vida de los pacientes. Dado que varias de las EDL comprometen al sistema osteoarticular, no es infrecuente que los pacientes consulten en primera instancia al reumatólogo. El objetivo de esta revisión es destacar los aspectos clínicos de aquellas EDL en las que se puede plantear el diagnóstico diferencial con patologías reumatológicas...

Multiplex newborn screening for Pompe, Fabry, Hunter, Gaucher, and Hurler diseases using a digital microfluidic platform.

PURPOSE: New therapies for lysosomal storage diseases (LSDs) have generated interest in screening newborns for these conditions. We present performance validation data on a digital microfluidic platform that performs multiplex enzymatic assays for Pompe, Fabry, Hunter, Gaucher, and Hurler diseases. METHODS: We developed an investigational disposable digital microfluidic cartridge that uses a single dried blood spot (DBS) punch for performing a 5-plex fluorometric enzymatic assay on up to 44 DBS samples. Precision and linearity of the assays were determined by analyzing quality control DBS samples; clinical performance was determined by analyzing 600 presumed normal and known affected samples (12 for Pompe, 7 for Fabry and 10 each for Hunter, Gaucher and Hurler). RESULTS: Overall coefficient of variation (CV) values between cartridges, days, instruments, and operators ranged from 2 to 21%; linearity correlation coefficients were ≥0.98 for all assays. The multiplex enzymatic assay performed from a single DBS punch was able to discriminate presumed normal from known affected samples for 5 LSDs. CONCLUSIONS: Digital microfluidic technology shows potential for rapid, high-throughput screening for 5 LSDs in a newborn screening laboratory environment. Sample preparation to enzymatic activity on each cartridge is less than 3h.

[Treatment prospects of lysosomal storage disorders]. / Lizoszomális tárolási rendellenességek kezelési lehetoségei.

Lysosomal storage disorders are caused either by deficiencies or decreased activity of enzymes localised in lysosomal vesicles or transport failure of these enzymes or their substrates. Accumulation of macromolecules destroy cell function presenting in clinical symptoms. Up to date, there are about 40 different lysosomal storage disorders according to the accumulated macromolecules. Till the last decades supportive therapy was the only option by these disorders. Enhanced researches in the last decades have presented some breakthrough results in the field of storage disease therapy. The review briefly introduces the lysosomal storage disorders, summarizes the actual therapy possibilities, as enzyme replacement therapy, substrate deprivation therapy, bone marrow transplantation. Finally, the review outlines future therapeutic potentials, like stem-cell and gene therapy.

Correlación clínico-patológica de enfermedades cutáneas de depósito lisosomal (I parte) / Clinico-pathological correlation of lysosomal storage skin diseases (part I)

Las enfermedades de depósito lisosomal corresponden a alteraciones congénitas del metabolismo, las cuales se heredan de forma autosómica recesiva y están caracterizadas por el déficit específico de una hidrolasa lisosomal y por el acúmulo de su sustrato en varios tejidos del organismo. Dependiendo de la naturaleza bioquímica del sustrato acumulado, éstas pueden dividirse en esfingolipidosis, oligosacaridosis, mucolipidosis, mucopolisacaridosis y otras.

Lysosomal storage diseases are autosomal recessive disorders of inborn errors of metabolism, characterized by a deficiency in a specific lysosomal hydrolase and by accumulation of its specific substrate in various body tissues. Depending on the basis of the biochemical nature of the accumulated substrate, they can be divided in sphingolipidoses, oligosaccharidoses, mucolipidoses, mucopolysaccharidoses, and others.

[Neurological presentations of lysosomal diseases in adult patients]. / Présentations neurologiques des maladies lysosomales chez l'adulte.

Lysosomal diseases represent a large group of genetic storage disorders characterized by a defect in the catabolism of complex molecules within the lysosome. Effective treatments are now possible for some of them given progresses in bone-marrow transplantation, enzyme replacement therapy and substrate reduction therapy. Neurologists and psychiatrists are concerned by these diseases because they can present in adolescence or adulthood with progressive neuropsychiatric signs. Here we focus on late-onset clinical forms which can be met in an adult neurology or psychiatric department. Lysosomal diseases were classified into 3 groups: (1) leukodystrophies (metachromatic leukodystrophy, Krabbe's disease and Salla's disease); (2) Neurodegenerative or psychiatric-like diseases (GM1 and GM2 gangliosidoses, Niemann Pick type C disease, sialidosis type I, ceroid-lipofuscinosis, mucopolysaccharidosis type III); (3) multisystemic diseases (Gaucher's disease, Fabry's disease, alpha and B mannosidosis, Niemann Pick disease type B, fucosidosis, Schindler/Kanzaki disease, and mucopolysaccharidosis type I and II. We propose a diagnostic approach guided by clinical examination, brain MRI, electrodiagnostic studies and abdominal echography.

Update on treatment of lysosomal storage diseases.

Lysosomal storage diseases (LSDs) are a large group of disorders caused by a deficiency of specific enzymes responsible for the degradation of substances present in lysosomes. In the past few years, treatments for LSDs were non specific and could only cope with signs and symptoms of the diseases. A successful therapeutic approach to LSDs should instead address to the underlying causes of the diseases, thus helping the degradation of the accumulated metabolites in the various organs, and at the same time preventing their further deposition. One way is to see to an available source of the deficient enzyme: bone marrow transplantation, enzyme replacement therapy and gene therapy are based on this rationale. The purpose of substrate reduction therapy is to down regulate the formation of the lysosomal substance to a rate at which the residual enzyme activity can catabolize the stored and de novo produced lysosomal substrate. Chemical chaperone therapy is based on small molecules able to bind and stabilize the misfolded enzymes. This paper offers a historical overview on the therapeutic strategies for LSDs.

[Lysosomal storage diseases: functional classification and treatment principles]. / Maladies de surcharge lysosomale: classification fonctionnelle et principes thérapeutiques.

Until recently, lysosomes were only considered as the place of macromolecules degradation. To date, these organelles are considered as playing a key role in cellular homeostasis. The knowledge of their complex role allows a better understanding of the physiopathology of the diseases resulting from their dysfunction. Biosynthesis of lysosomal enzymes and routes for macromolecules influx within lysosomes are briefly described and a functional classification of lysosomal diseases, which allows a comprehensive approach of treatment rationale, is proposed. Except cystinosis which is a lysosomal membrane transport disorder the majority of current treatments aim at treating enzymatic defects. Normal enzyme can be brought by hoematopoietic cell transplant (or other cell therapies) or by infusions of human recombinant enzyme. The normal enzyme can be also produced in situ by bringing the normal gene: it is the objective of gene therapy The other therapeutic approaches aim at decreasing the quantity of non degraded substrate reaching the lysosomes by limiting its biosynthesis or thanks to small pharmacologic molecules, at increasing the residual enzyme activity by stabilizing the protein (chaperones) or by improving read through possibilities of some stop codons in special contexts. The better knowledge of secondary phenomena set by the cell in order to try to restore homeostasis which are sometimes more deleterious than the storage itself should allow to develop complementary treatments. The rationale of these different therapeutic approaches and their limits are described in this paper

Pharmacotherapeutic strategies using small molecules for the treatment of glycolipid lysosomal storage disorders.

The glycolipid lysosomal storage diseases are a collection of rare, inherited disorders of metabolism associated with heterogeneous pathologies and reduced life expectancy. Reduction of the substrate that accumulates due to catabolic enzyme deficiency can be mediated by an increasing number of therapeutic approaches, including enzyme replacement, pharmacological intervention to reduce substrate synthesis or enhance residual enzyme activity, and cell or gene therapy. The success of one agent, the imino sugar miglustat, has provided the impetus for using similar molecules for enzyme enhancement, or chaperone-mediated therapy for exiting medical conditions and for conditions where no disease-specific therapy is available. The advantages of using small molecules as therapy for the family of lysosomal storage disorders are discussed with reference to existing enzyme replacement therapies.

The emerging role of the pediatric physical therapist in evaluation and intervention for individuals with lysosomal storage diseases.

PURPOSE: The purposes of this article are to describe the pathology, medical implications, and typical impairments of individuals with various lysosomal storage diseases (LSDs), summarize results of recent clinical trials on medical interventions relevant to physical therapy practice, report new advances in functional measurement, and suggest a framework for physical therapy management and intervention. SUMMARY OF KEY POINTS: Medical and surgical interventions are enabling individuals with LSDs to not only survive but to improve their daily functioning and quality of life. This is likely to become an increasing area of emphasis in pediatric physical therapy, as the intervention emphasis for some individuals will shift from maintenance to restorative programs. RECOMMENDATIONS: We recommend that pediatric physical therapists become familiar with new LSD therapeutics, play a major role in evaluating impairment and functional limitation changes in individuals with LSDs, and become knowledgeable about the indications and precautions for restorative physical therapy programs.

Neurological manifestations in lysosomal storage disorders - from pathology to first therapeutic possibilities.

Lysosomal storage disorders (LSDs) represent a large and heterogeneous group of inborn errors of metabolism with a rare incidence for the single disease but a respectable overall incidence of 1 in 7700 live births. Neurological involvement in LSDs is quite common and in the last years knowledge about the pathology and clinical course of LSDs has been rapidly increased. Enormous progress has been made in the treatment of LSDs by enzyme replacement, substrate reduction and research on gene therapy. This review aims to describe the progress made as well as the present limitations in this particular field of metabolic medicine. It focuses on those storage disorders with major neurological symptoms or complications where treatment is already available (Gaucher disease, Fabry disease, mucopolysaccharidosis type I) or predictable (Pompe disease, MPS II, MPS IV, MPS VI).

Lactosylceramide in lysosomal storage disorders: a comparative immunohistochemical and biochemical study.

Immunohistochemical studies of the presence of lactosylceramide (LacCer) in lysosomal storage disorders (LSDs) were done using anti-LacCer monoclonal antibody of the CDw 17 type (clone MG-2). No sign of an association between LacCer and the lysosomal system in normal cells was observed, except for histiocytes active in phagocytosis. A comparative study of a group of LSDs showed a general tendency for LacCer to increase in storage cells in Niemann-Pick disease type C (NPC), and types A and B, GM1 gangliosidosis, acid lipase deficiency, glycogen storage disease type II and mucopolysaccharidoses. LacCer accumulated in storage cells despite normal activity of relevant lysosomal degrading enzymes. The accumulation of LacCer displayed variability within storage cell populations, and was mostly expressed in neurons in NPC. An absence of the increase in LacCer in storage cells above control levels was seen in neuronal ceroid lipofuscinoses (neurons and cardiocytes) and in Fabry disease. Gaucher and Krabbe cells showed significantly lower levels, or even the absence, of LacCer compared with control macrophages. Results of immunohistochemistry were corroborated by semiquantitative lipid thin-layer chromatography (TLC). It is suggested that different associations of LacCer with the lysosomal storage process may reflect differences in glycosphingolipid turnover induced by the storage-compromised lysosomal/endosomal system.