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

Cardiac disease in patients with mucopolysaccharidosis: presentation, diagnosis and management

The mucopolysaccharidoses (MPSs) are inherited lysosomal storage disorders caused by the absence of functional enzymes that contribute to the degradation of glycosaminoglycans (GAGs). The progressive systemic deposition of GAGs results in multi-organ system dysfunction that varies with the particular GAG deposited and the specific enzyme mutation(s) present. Cardiac involvement has been reported in all MPS syndromes and is a common and early feature, particularly for those with MPS I, II, and VI. Cardiac valve thickening, dysfunction (more severe for left-sided than for right-sided valves), and hypertrophy are commonly present; conduction abnormalities, coronary artery and other vascular involvement may also occur. Cardiac disease emerges silently and contributes significantly to early mortality

Glycogen storage disease type Ia: molecular study in Brazilian patients

Mutations in the glucose-6-phosphatase (G6Pase) gene are responsible for glycogen storage disease type Ia (GSDIa). This disease is characterized by growth retardation, hepatomegaly, hypoglycemia, hyperlipidemia, and lactic acidosis. In this study, we report mutations in the G6Pase gene in 8 of 25 Brazilian patients with clinical symptoms of GSDIa. Five previously described mutations (R83C, Q347X, V338F, D38V, and G68R) were detected. The two most common mutations identified were R83C and Q347X, accounting for 8 of 14 (57.14%) mutant alleles. A 1176 single-nucleotide polymorphism and two intronic mutations (IVS3-58T>A and IVS4+10G>A) were also analyzed. We used the minigene strategy in order to verify the effect of these intronic mutations on the splicing mechanism. This study emphasizes that molecular genetic analysis is a reliable and convenient alternative to the assay of enzyme activity in a fresh liver biopsy specimen for dianosing GSDIa.46314614

Ethical issues related to the access to orphan drugs in Brazil: the case of mucopolysaccharidosis type I

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Background/Aims Mucopolysaccharidosis type I (MPS I) is a rare lysosomal storage disorder treated with bone marrow transplantation or enzyme replacement therapy with laronidase, a high-cost orphan drug. Laronidase was approved by the US Food and Drug Administration and the European Medicines Agency in 2003 and by the Brazilian National Health Surveillance Agency in 2005. Many Brazilian MPS I patients have been receiving laronidase despite the absence of a governmental policy regulating access to the drug. Epidemiological and treatment data concerning MPS I are scarce. This study aims to present a demographic profile of Brazilian patients with MPS I, describe the routes of access to laronidase in Brazil, and discuss associated ethical issues relating to public funding of orphan drugs. Methods In this cross-sectional observational study, data were collected nationwide between January and September 2008 from physicians, public institutions and non-governmental organisations involved with diagnosis and treatment of MPS I, using two data collection instruments specifically designed for this purpose. Results The minimum prevalence of MPS I in Brazil was estimated at 1/2 700 000. Most patients (69.8%) were younger than 15 years; 60 (88.2%) received laronidase. The most common route of access to the drug was through lawsuits (86.6%). Conclusions In Brazil, MPS I is predominantly a paediatric illness. Even though the cost of laronidase treatment is not officially covered by the Brazilian government, most MPS I patients receive the drug, usually through litigation. This gives rise to major ethical conflicts concerning drug access in a low-resource context. The Brazilian health policy framework lacks evidence-based clinical protocols for the distribution of orphan drugs.374233239Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq [033/2007

Dentomaxillofacial manifestations of mucopolysaccharidosis VI: clinical and imaging findings from two cases, with an emphasis on the temporomandibular joint

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Objectives. Using a clinical survey, panoramic, cone-beam computed tomography (CBCT), and magnetic resonance (MR) imaging, this study was conducted to ascertain primary maxillofacial abnormalities in patients with mucopolysaccharidosis VI (MPS VI). Study design. Two patients previously diagnosed with MPS VI underwent clinical and imaging surveys (panoramic radiographs, CBCT, and MR imaging). Results. Jaw involvement was present in all patients. The most prevalent findings were enlarged marrow spaces, osteopenia, dentigerous cyst-like follicles, effacement of the jaw structures, and osteosclerosis. This is the first study to describe temporomandibular joint (TMJ) involvement for MPS VI. Conclusions. CBCT and MR imaging were needed to observe features that were not clear in conventional radiographs. Both patients reported symptoms in the TMJ and demonstrated involvement during their examinations. A multicenter study is necessary to better document maxillofacial involvement in MPS VI.1162E141E148Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq [573993/2008-4

Universal newborn screening: A roadmap for action.

Newborn screening (NBS) prevents morbidity and mortality by screening babies for selected disorders in the first days of life so that early diagnosis and treatment can be initiated. Congenital disorders impact an estimated 8 million or 6% of annual births worldwide, and of the top five that contribute 25% to the global burden of these disorders, three can be identified and managed by NBS. There are determined pockets of activity in Latin America, Sub-Saharan Africa, and the Asia Pacific region, where partnerships among government, non-governmental organizations, academia, the private sector and civil society are developing novel NBS programs that are both saving lives and preventing disability in those who survive

Universal newborn screening: A roadmap for action.

Newborn screening (NBS) prevents morbidity and mortality by screening babies for selected disorders in the first days of life so that early diagnosis and treatment can be initiated. Congenital disorders impact an estimated 8 million or 6% of annual births worldwide, and of the top five that contribute 25% to the global burden of these disorders, three can be identified and managed by NBS. There are determined pockets of activity in Latin America, Sub-Saharan Africa, and the Asia Pacific region, where partnerships among government, non-governmental organizations, academia, the private sector and civil society are developing novel NBS programs that are both saving lives and preventing disability in those who survive