Relative frequency and estimated minimal frequency of Lysosomal Storage Diseases in Brazil: Report from a Reference Laboratory

Abstract Lysosomal storage diseases (LSDs) comprise a heterogeneous group of more than 50 genetic conditions of inborn errors of metabolism (IEM) caused by a defect in lysosomal function. Although there are screening tests for some of these conditions, diagnosis usually depends on specific enzyme assays, which are only available in a few laboratories around the world. A pioneer facility for the diagnosis of IEM and LSDs was established in the South of Brazil in 1982 and has served as a reference service since then. Over the past 34 years, samples from 72,797 patients were referred for investigation of IEM, and 3,211 were confirmed as having an LSD (4.41%, or 1 in 22), with 3,099 of these patients originating from Brazil. The rate of diagnosis has increased over time, in part due to the creation of diagnostic networks involving a large number of Brazilian services. These cases, referred from Brazilian regions, provide insight about the relative frequency of LSDs in the country. The large amount of data available allows for the estimation of the minimal frequency of specific LSDs in Brazil. The reported data could help to plan health care policies, as there are specific therapies available for most of the cases diagnosed.

Enzyme Replacement Therapy With Elosulfase Alfa Decreases Storage of Glycosaminoglycan in White Blood Cells of Patients With Morquio A Syndrome

Abstract Mucopolysaccharidosis IVA (MPS IVA; Morquio A syndrome) is a lysosomal storage disorder caused by a deficient N-acetylgalactosamine-6-sulfate sulfatase activity, leading to cellular storage of undegraded keratan sulfate. Recently enzyme replacement therapy (ERT) was approved for MPS IVA, but some of ERT effects are still unknown. In the present study, we aimed to evaluate the efficacy of elosulfase alfa upon glycosaminoglycan (GAG) storage in peripheral blood white blood cells of patients with MPS IVA treated for 6 months, comparing samples from patients who received weekly infusions of enzyme (ERT-W) versus infusions every other week (ERT-EOW) versus placebo. A significant reduction in GAG storage was observed in both ERT-treated groups, with weekly ERT showing slightly better performance than ERT-EOW.

Terapia de reposição enzimática para as mucopolissacaridoses I, II e VI: recomendações de um grupo de especialistas brasileiros / Enzyme replacement therapy for mucopolysaccharidoses I, II and VI: recommendations from a group of Brazilian F experts

As mucopolissacaridoses (MPS) são doenças genéticas raras causadas pela deficiência de enzimas lisossômicas específicas que afetam o catabolismo de glicosaminoglicanos (GAG). O acúmulo de GAG em vários órgãos e tecidos nos pacientes afetados pelas MPS resulta em uma série de sinais e sintomas, integrantes de um quadro clínico multissistêmico que compromete ossos e articulações, vias respiratórias, sistema cardiovascular e muitos outros órgãos e tecidos, incluindo, em alguns casos, as funções cognitivas. Já foram identificados 11 defeitos enzimáticos que causam sete tipos diferentes de MPS. Antes do advento de terapias dirigidas para a restauração da atividade da enzima deficiente, o tratamento das MPS tinha como principal foco a prevenção e o cuidado das complicações, aspecto ainda bastante importante no manejo desses pacientes. Na década de 80 foi proposto o tratamento das MPS com transplante de medula óssea/transplante de células tronco hematopoiéticas (TMO/TCTH) e na década de 90 começou o desenvolvimento da Terapia de Reposição Enzimática (TRE), que se tornou uma realidade aprovada para uso clínico nas MPS I, II e VI na primeira década do século 21. Os autores deste trabalho têm a convicção de que um melhor futuro para os pacientes afetados pelas MPS depende da identificação, compreensão e manejo adequado das manifestações multissistêmicas dessas doenças, incluindo medidas de suporte (que devem fazer parte da assistência multidisciplinar regular destes pacientes) e terapias específicas...

Mucopolysaccharidoses (MPS) are rare genetic diseases caused by deficiency of specific lysosomal enzymes that affect catabolism of glycosaminoglycans (GAG). Accumulation of GAG in various organs and tissues in MPS patients results in a series of signs and symptoms, producing a multisystemic condition affecting bones and joints, the respiratory and cardiovascular systems and many other organs and tissues, including in some cases, cognitive performance. So far, eleven enzyme defects that cause seven different types of MPS have been identified. Before introduction of therapies to restore deficient enzyme activity, treatment of MPS focused primnarily on prevention and care of complications, still a very important aspect in the management of these patients. In the 80's treatment of MPS with bone marrow transplantation/hematopoietic stem cells transplantation (BMT/HSCT) was proposed and in the 90's, enzyme replacement therapy (ERT),began to be developed and was approved for clinical use in MPS I, II and VI in the first decade of the 21st century. The authors of this paper are convinced that a better future for patients affected by mucopolysaccharidoses depends upon identifying, understanding and appropriately managing the multisystemic manifestations of these diseases. This includes the provision of support measures (which should be part of regular multidisciplinary care of these patients) and of specific therapies...

Mucopolysaccharidosis I, II, and VI: brief review and guidelines for treatment

Mucopolysaccharidoses (MPS) are rare genetic diseases caused by the deficiency of one of the lysosomal enzymes involved in the glycosaminoglycan (GAG) breakdown pathway. This metabolic block leads to the accumulation of GAG in various organs and tissues of the affected patients, resulting in a multisystemic clinical picture, sometimes including cognitive impairment. Until the beginning of the XXI century, treatment was mainly supportive. Bone marrow transplantation improved the natural course of the disease in some types of MPS, but the morbidity and mortality restricted its use to selected cases. The identification of the genes involved, the new molecular biology tools and the availability of animal models made it possible to develop specific enzyme replacement therapies (ERT) for these diseases. At present, a great number of Brazilian medical centers from all regions of the country have experience with ERT for MPS I, II, and VI, acquired not only through patient treatment but also in clinical trials. Taking the three types of MPS together, over 200 patients have been treated with ERT in our country. This document summarizes the experience of the professionals involved, along with the data available in the international literature, bringing together and harmonizing the information available on the management of these severe and progressive diseases, thus disclosing new prospects for Brazilian patients affected by these conditions.