Respiratory muscular strength in children with mucopolysacaridosis: comparison with predictive equations.

BACKGROUND: Mucopolysaccharidoses (MPS) are rare metabolic diseases that impair respiratory function leading to respiratory failure. This study aimed to compare maximal inspiratory and expiratory pressures (MIP and MEP) obtained in children with MPS and compare with predicted values from previous studies involving healthy children. METHODS: This is a cross-sectional study, in which the chest deformity was evaluated; MIP, MEP through digital manometer, and lung function through spirometry. MIP and MEP were compared with five different predict equations and with a control group of healthy children. Agreement between respiratory muscle weakness regarding absolute values of MIP and MEP in relation to predictive values by the equations included in the study were assessed by Kappa coefficient. RESULTS: MPS group was composed of 22 subjects. 45.5% had pectus carinatum, 36.4% pectus excavatum, and presented lower MIP (37.14±36.23 cmH2O) and MEP (60.09±22.3 cmH2O) compared with control group (22 healthy subjects) (MIP: 91.45±35.60; MEP: 95.73±22.38). Only the MEP equations proposed by Tomalak et al. were close to those found in our MPS children (P=0.09). In the MPS group it was observed a weak agreement between inspiratory weakness through absolute and predicted values in only two equations: Tomalak et al. and Domenèch-Clar et al. (for both: k=0.35, P value =0.03); and for MEP a moderate agreement was found using all predictive equations. CONCLUSIONS: In MPS children MRP data should not be normalized using the reference equations for healthy ones, is more coherent to longitudinally follow absolute pressures and lung volumes in this group.

MPSBase: Comprehensive repository of differentially expressed genes for mucopolysaccharidoses.

Mucopolysaccharidoses (MPS) are lysosomal storage diseases (LSDs) caused by the deficiency of enzymes essential for the metabolism of extracellular matrix components called glycosaminoglycans (GAGs). To understand the physiopathology and alterations due to the lysosomal accumulation resulting from enzymatic deficiencies and their secondary outcomes can improve the diagnosis and treatment of rare genetic diseases. This work presents a database for differentially expressed genes from different public MPS data. We developed our database, including 13 studies previously deposited in the GEO (https://www.ncbi.nlm.nih.gov/geo/). The website is hosted in the UFRGS data processing center (CPD) and is available at . The site was constructed in PHP, and the analyses were performed in R. The organisms represented by the datasets are Canis lupus familiaris, Homo sapiens, Mus musculus, and Rattus norvegicus. The user can search for the differentially expressed genes and ontologies by species, MPS type, or tissue type. For each comparison, a heatmap with the 50 top differentially expressed genes is available as well as dot plots for the 30 top ontologies divided by biological process, cellular component, KEGG pathways, and molecular function. This data is also fully available in tables. There are 54 possible comparisons involving about 5000 to 10,000 genes each. This website is the only specific database for MPS with filtering and presenting their results in a one-click approach to the best of our knowledge. The development of such analytical and automated strategies accessible to health professionals is essential for fostering MPS research. The MPSBase is a web user-friendly, comprehensive repository of differentially expressed genes and ontologies regarding the MPS data.

Applying the functional independence measure to the assessment of patients with mucopolysaccharidosis / Test de medida de independencia funcional en la evaluación de pacientes con mucopolisacaridosis

Abstract Objective: To assess the functional independence of a group of patients with mucopolysaccharidosis using the Functional Independence Measure as a tool that accomplishes this purpose. Methods: This is a cross-sectional study of patients with mucopolysaccharidosis. Our data was collected between June 2015 and July 2016. In addition to history of present illness and physical examination each study participant was asked to answer a questionnaire to specifically evaluate their functional independence using the functional independence measure. the internal consistency of the functional independence measure was assessed using Cronbach's alpha coefficient. Results: We collected data on 20 patients with mucopolysaccharidosis. The average age was 10.8 (8.67-13.03) years, the average weight was 23.6 (19.91-27.37) kg and the average height was 1 (0.83-1.17) m. The most prevalent type of mucopolysaccharidosis in the study was type VI (n= 14). The average total functional independence measure score was 104.4 (97.61-111.19), the average for the mobility domain was 73.50 (68.22-78.78) and the average for the cognitive function domain was 30.90 (28.68-33.13). The internal consistency of the entire questionnaire was 0.859, with values of 0.966 for the mobility domain and 0.624 for the cognitive function domain. Conclusion: The lowest functional independence measure scores were obtained in the following sub-domains: self-care, locomotion and cognitive function. The functional independence measure questionnaire demonstrated internal consistency for the evaluation of functional independence in patients with mucopolysaccharidosis, being able to value all the affected sub-domains separately.

Resumen Objetivo: Evaluar la independencia funcional de un grupo de pacientes con mucopolisacaridosis utilizando la Medida de Independencia Funcional como herramienta para lograr este propósito. Métodos: Este es un estudio transversal de pacientes con mucopolisacaridosis. Nuestros datos se recopilaron entre junio de 2015 y julio de 2016. Además de la historia de la enfermedad actual y el examen físico, se pidió a cada participante del estudio que respondiera un cuestionario para evaluar específicamente su independencia funcional utilizando la Medida de Independencia Funcional. la consistencia interna de la Medida de Independencia Funcional se evaluó mediante el coeficiente alfa de Cronbach. Resultados: Recopilamos datos de 20 pacientes con mucopolisacaridosis. La edad promedio fue de 10.8 (8.67-13.03) años, el peso promedio fue de 23.6 (19.91-27.37) kg y la altura promedio fue de 1 m (0.83-1.17). El tipo de mucopolisacaridosis más prevalente en el estudio fue el tipo VI (n= 14). El puntaje promedio de la medida de independencia funcional total fue 104.4 (97.61-111.19), el promedio para el dominio de movilidad fue 73.50 (68.22-78.78) y el promedio para el dominio de función cognitiva fue 30.90 (28.68-33.13). La consistencia interna de todo el cuestionario fue de 0.859, con valores de 0.966 para el dominio de movilidad y 0.624 para el dominio de función cognitiva. Conclusión: Las puntuaciones más bajas de la medida de independencia funcional se obtuvieron en los siguientes subdominios: autocuidado, locomoción y función cognitiva. El cuestionario de medida de independencia funcional demostró consistencia interna para la evaluación de la independencia funcional en pacientes con mucopolisacaridosis, pudiendo valorar todos los subdominios afectados por separado.

Applying the functional independence measure to the assessment of patients with mucopolysaccharidosis.

OBJECTIVE: To assess the functional independence of a group of patients with mucopolysaccharidosis using the Functional Independence Measure as a tool that accomplishes this purpose. METHODS: This is a cross-sectional study of patients with mucopolysaccharidosis. Our data was collected between June 2015 and July 2016. In addition to history of present illness and physical examination each study participant was asked to answer a questionnaire to specifically evaluate their functional independence using the functional independence measure. the internal consistency of the functional independence measure was assessed using Cronbach's alpha coefficient. RESULTS: We collected data on 20 patients with mucopolysaccharidosis. The average age was 10.8 (8.67-13.03) years, the average weight was 23.6 (19.91-27.37) kg and the average height was 1 (0.83-1.17) m. The most prevalent type of mucopolysaccharidosis in the study was type VI (n= 14). The average total functional independence measure score was 104.4 (97.61-111.19), the average for the mobility domain was 73.50 (68.22-78.78) and the average for the cognitive function domain was 30.90 (28.68-33.13). The internal consistency of the entire questionnaire was 0.859, with values of 0.966 for the mobility domain and 0.624 for the cognitive function domain. CONCLUSION: The lowest functional independence measure scores were obtained in the following sub-domains: self-care, locomotion and cognitive function. The functional independence measure questionnaire demonstrated internal consistency for the evaluation of functional independence in patients with mucopolysaccharidosis, being able to value all the affected sub-domains separately.

OBJETIVO: Evaluar la independencia funcional de un grupo de pacientes con mucopolisacaridosis utilizando la Medida de Independencia Funcional como herramienta para lograr este propósito. MÉTODOS: Este es un estudio transversal de pacientes con mucopolisacaridosis. Nuestros datos se recopilaron entre junio de 2015 y julio de 2016. Además de la historia de la enfermedad actual y el examen físico, se pidió a cada participante del estudio que respondiera un cuestionario para evaluar específicamente su independencia funcional utilizando la Medida de Independencia Funcional. la consistencia interna de la Medida de Independencia Funcional se evaluó mediante el coeficiente alfa de Cronbach. RESULTADOS: Recopilamos datos de 20 pacientes con mucopolisacaridosis. La edad promedio fue de 10.8 (8.67-13.03) años, el peso promedio fue de 23.6 (19.91-27.37) kg y la altura promedio fue de 1 m (0.83-1.17). El tipo de mucopolisacaridosis más prevalente en el estudio fue el tipo VI (n= 14). El puntaje promedio de la medida de independencia funcional total fue 104.4 (97.61-111.19), el promedio para el dominio de movilidad fue 73.50 (68.22-78.78) y el promedio para el dominio de función cognitiva fue 30.90 (28.68-33.13). La consistencia interna de todo el cuestionario fue de 0.859, con valores de 0.966 para el dominio de movilidad y 0.624 para el dominio de función cognitiva. CONCLUSIÓN: Las puntuaciones más bajas de la medida de independencia funcional se obtuvieron en los siguientes subdominios: autocuidado, locomoción y función cognitiva. El cuestionario de medida de independencia funcional demostró consistencia interna para la evaluación de la independencia funcional en pacientes con mucopolisacaridosis, pudiendo valorar todos los subdominios afectados por separado.

Audiometric evaluation in individuals with mucopolysaccharidosis.

OBJECTIVES: To characterize the audiometric evaluation and acoustic immittance measures in different types of mucopolysaccharidosis. METHOD: Fifty-three mucopolysaccharidosis patients were evaluated. The classification consisted of type I (Hurler syndrome, Hurler-Scheie and Scheie syndrome), type II (Hunter syndrome), type III (Sanfilippo syndrome), type IV (Morquio syndrome), and type VI (Maroteaux-Lamy syndrome). Immittance audiometry and play or conventional threshold tone audiometry were used to obtain auditory thresholds and were chosen according to the patient's chronological age and ability to understand/respond to the procedure. The findings were analyzed using descriptive statistics and considering the recommendations for research involving human beings contained in Resolution CNE N° 466/2012. RESULTS: Fifty-one subjects (96.2%) had hearing loss, and the conductive type was the most frequent. Only two (3.8%) patients presented bilateral thresholds within normal limits, one with type IV mucopolysaccharidosis and the other with type VI. There were 11 individuals (20.8%) with mucopolysaccharidosis type I with mixed hearing loss, 9 (16.9%) individuals with type I with conductive hearing loss and 9 (16.9%) with type VI with conductive hearing loss. Mild hearing loss was most common (37.3%), followed by moderately severe hearing loss (36.3%). The type B tympanometric curve (80.4%) was the most frequent. CONCLUSIONS: Most of the individuals with mucopolysaccharidosis types I, II, III, IV and VI presented mixed or conductive hearing losses of mild to moderately severe degree, type B tympanograms and an absence of contralateral acoustic reflexes.

Audiometric evaluation in individuals with mucopolysaccharidosis

OBJECTIVES: To characterize the audiometric evaluation and acoustic immittance measures in different types of mucopolysaccharidosis. METHOD: Fifty-three mucopolysaccharidosis patients were evaluated. The classification consisted of type I (Hurler syndrome, Hurler-Scheie and Scheie syndrome), type II (Hunter syndrome), type III (Sanfilippo syndrome), type IV (Morquio syndrome), and type VI (Maroteaux-Lamy syndrome). Immittance audiometry and play or conventional threshold tone audiometry were used to obtain auditory thresholds and were chosen according to the patient's chronological age and ability to understand/respond to the procedure. The findings were analyzed using descriptive statistics and considering the recommendations for research involving human beings contained in Resolution CNE N° 466/2012. RESULTS: Fifty-one subjects (96.2%) had hearing loss, and the conductive type was the most frequent. Only two (3.8%) patients presented bilateral thresholds within normal limits, one with type IV mucopolysaccharidosis and the other with type VI. There were 11 individuals (20.8%) with mucopolysaccharidosis type I with mixed hearing loss, 9 (16.9%) individuals with type I with conductive hearing loss and 9 (16.9%) with type VI with conductive hearing loss. Mild hearing loss was most common (37.3%), followed by moderately severe hearing loss (36.3%). The type B tympanometric curve (80.4%) was the most frequent. CONCLUSIONS: Most of the individuals with mucopolysaccharidosis types I, II, III, IV and VI presented mixed or conductive hearing losses of mild to moderately severe degree, type B tympanograms and an absence of contralateral acoustic reflexes.

Phase I and II clinical trials for the mucopolysaccharidoses.

INTRODUCTION: The mucopolysaccharidoses are lysosomal diseases characterized by deficient activity of one of the enzymes that degrades glycosaminoglycans. Treatment options are limited; therefore, new treatments are under investigation. Areas covered: We review the medicinal products for the treatment of mucopolysaccharidoses that are currently being investigated in phase I and phase II clinical trials. Expert opinion: The number of alternatives to treat MPS diseases increased dramatically in an attempt to provide therapy options for orphan MPS diseases and to address the unmet needs of the MPS that already have a treatment available. Intravenous enzyme replacement therapy (ERT) with fusion proteins, intrathecal/intracerebroventricular (ICV) ERT and gene therapy are the most promising strategies addressing the CNS manifestations. Stop-codon read-through, although proposed only for patients with nonsense mutations, might be useful in all MPS types. Substrate reduction therapy could also play a role in any MPS type, as anti-inflammatory drugs are also being tested. This new generation of therapies is now in clinical development and should bring new hope to MPS patients. As cost and logistics remain major challenges, especially for low- and middle-income countries, the possibility of having a one-time treatment such as gene therapy is anxiously awaited by affected families and healthcare systems.

Mucopolisacaridosis: características clínicas, diagnóstico y de manejo / Mucopolysaccharidosis: clinical features, diagnosis and management

Las mucopolisacaridosis (MPS) son un grupo de enfermedades raras (huérfanas), de baja prevalencia, caracterizadas por la deficiencia de enzimas que participan en el metabolismo de glucosaminglucanos (GAG) a nivel lisosomal. Se caracteriza por acumulación de GAG intracelular, produciendo alteraciones de múltiples órganos y sistemas. Su diagnóstico se basa en el conocimiento de las manifestaciones clínicas, realizar el análisis bioquímico para identificar el tipo de GAG que se está acumulando y confirmar el tipo de enfermedad con la determinación enzimática correspondiente. Su identificación es fundamental para iniciar un tratamiento oportuno, teniendo en cuenta que actualmente existe manejo transdisciplinario y tratamiento de reemplazo enzimático para MPS I (síndrome de Hurler), MPS II (síndrome de Hunter), MPS IV (síndrome de Morquio) y MPS VI (síndrome de Maroteaux-Lamy). En esta revisión se analizan cada uno de estos síndromes, su diagnóstico y tratamiento.

The mucopolysaccharidoses (MPS) are a group of rare (orphan) diseases, characterised by a deficiency of enzymes involved in the metabolism of glycosaminoglycans (GAGs) at lysosomal level. When there is a deficiency of a particular enzyme there is an accumulation of GAGs in the cells resulting in progressive cellular damage, which can affect multiple organ systems and lead to organ failure. Diagnosis is based on knowledge of the clinical manifestations, performing biochemical analyses to identify the type of GAG that is accumulating, and confirm the type of disorder with the corresponding enzymatic determination. Their identification is essential to initiate early treatment, taking into account that multidisciplinary management and enzyme replacement therapy is available for MPS I (Hurler syndrome), MPS II (Hunter syndrome), MPS IV (Morquio syndrome), and MPS VI (Maroteaux-Lamy syndrome. In this review, an analysis is made of each of these syndromes, as well as their diagnosis and treatment.

Emerging drugs for the treatment of mucopolysaccharidoses.

INTRODUCTION: Despite being reported for the first time almost one century ago, only in the last few decades effective have treatments become available for the mucopolysaccharidoses (MPSs), a group of 11 inherited metabolic diseases that affect lysosomal function. These diseases are progressive, usually severe, and, in a significant number of cases, involve cognitive impairment. AREAS COVERED: This review will not cover established treatments such as bone marrow/hematopoietic stem cell transplantation and classic intravenous enzyme replacement therapy (ERT), whose long-term outcomes have already been published (MPS I, MPS II, and MPS VI), but it instead focuses on emerging therapies for MPSs. That includes intravenous ERT for MPS IVA and VII, intrathecal ERT, ERT with fusion proteins, substrate reduction therapy, gene therapy, and other novel approaches. EXPERT OPINION: The available treatments have resulted in improvements for several disease manifestations, but they still do not represent a cure for these diseases; thus, it is important to develop alternative methods to approach the unmet needs (i.e. bone disease, heart valve disease, corneal opacity, and central nervous system (CNS) involvement). The work in progress with novel approaches makes us confident that in 2017, when MPS will commemorate 100 years of its first report, we will be much closer to an effective cure for these challenging conditions.

[Mucopolysaccharidosis: clinical features, diagnosis and management]. / Mucopolisacaridosis: características clínicas, diagnóstico y de manejo.

The mucopolysaccharidoses (MPS) are a group of rare (orphan) diseases, characterised by a deficiency of enzymes involved in the metabolism of glycosaminoglycans (GAGs) at lysosomal level. When there is a deficiency of a particular enzyme there is an accumulation of GAGs in the cells resulting in progressive cellular damage, which can affect multiple organ systems and lead to organ failure. Diagnosis is based on knowledge of the clinical manifestations, performing biochemical analyses to identify the type of GAG that is accumulating, and confirm the type of disorder with the corresponding enzymatic determination. Their identification is essential to initiate early treatment, taking into account that multidisciplinary management and enzyme replacement therapy is available for MPS I (Hurler syndrome), MPS II (Hunter syndrome), MPS IV (Morquio syndrome), and MPS VI (Maroteaux-Lamy syndrome. In this review, an analysis is made of each of these syndromes, as well as their diagnosis and treatment.

Functional capacity evaluation of patients with mucopolysaccharidosis.

INTRODUCTION: The mucopolysaccharidoses (MPS) are rare genetic disorders caused by a deficiency in lysosomal enzymes that affect the catabolism of glycosaminoglycans and cause their accumulation, resulting in a multisystemic clinical picture. Their clinical manifestations result in limited ability to perform daily life tasks. OBJECTIVES: To evaluate functional capacity and joint range of motion (ROM) in patients with MPS followed at the reference center for lysosomal disorders at Hospital de Clínicas de Porto Alegre, Brazil. METHODS: This was a prospective longitudinal study with a convenience sample. The Pediatric Evaluation of Disability Inventory (PEDI) and the Functional Independence Measure (FIM) were used to evaluate functionality and goniometry was used to evaluate ROM at three times (baseline, 6 months, and 12 months after study inclusion). An exploratory analysis was done of the effect of enzyme replacement therapy (ERT) in both variables; thus, patients were divided into Group 1 (patients without ERT), Group 2 (patients on ERT before and after study inclusion), and Group 3 (patients who started ERT after study inclusion). RESULTS: 21 patients were included: 7 in Group 1 (MPS II: 3, MPS III-B: 2, MPS IV-A: 2), 6 in Group 2 (MPS I: 3; MPS VI: 3), and 8 in Group 3 (MPS I: 3, MPS II: 4, MPS VI: 1). A limitation in the mobility of all joints studied was found especially in MPS I, II, and VI. Functionality compromise was also frequent (PEDI=5/7 patients; MIF=9/14 patients), even in individuals with preserved cognition. No correlation was found between the findings of goniometry and the PEDI domains (self-care, mobility, social function). ERT did not seem to significantly change the parameters analyzed. DISCUSSION/CONCLUSION: The compromise of joint mobility and functionality seems to be common in MPS I, II, III-B, IV-A, and VI. This finding is in line with the fact that, although these types of MPS are caused by different genetic defects, they share metabolic routes and physiopathogenic processes and present similar clinical manifestations. The preservation of functionality is an increasing challenge in the treatment of MPS patients, and maintenance of occupational performance should be defined as an objective to be reached by therapies used. Further studies with a greater sample size are necessary in order to verify the effect of ERT in these variables.

Evaluation of orofacial motricity in patients with mucopolysaccharidosis: a cross-sectional study.

OBJECTIVES: To characterize the stomatognathic system and stomatognathic functions in patients with mucopolysaccharidosis. METHODS: Cross-sectional and observational study of patients with mucopolysaccharidosis seen at the outpatient clinic at the Medical Genetics Service of Hospital de Clínicas de Porto Alegre. The inclusion criteria were the existence of a biochemical or molecular diagnosis of any type of mucopolysaccharidosis and the agreement to participate in the study by signing an informed consent form. Seventy-eight patients were evaluated through phonoaudiological anamnesis and physical exam. RESULTS: Alterations in at least one item of each structure of the stomatognathic system or stomatognathic function were found in all patients who allowed evaluation of both items on physical examination (n = 76/78). The most frequently compromised structures and functions were respectively the dental arch and the tongue, swallowing and mastication. The only statistically significant difference found between types of mucopolysaccharidosis involved the habitual position of the tongue between the teeth (most frequent in mucopolysaccharidosis VI). Among patients with mucopolysaccharidosis I, II or VI who underwent enzyme replacement therapy or not, there was statistically significant difference in oral breathing mode (more frequent in the group without enzyme replacement therapy). CONCLUSIONS: Alterations in stomatognathic systems and functions are prevalent among individuals with mucopolysaccharidosis, even if enzyme replacement therapy is administered. Such finding suggests that speech therapy follow-up plays a major role in the treatment plan of this group of diseases; this hypothesis should be confirmed by additional studies.

Avaliação da motricidade orofacial em pacientes com mucopolissacaridose: um estudo transversal / Evaluation of orofacial motricity in patients with mucopolysaccharidosis: a cross-sectional study

OBJETIVO: Caracterizar o sistema estomatognático e as funções estomatognáticas de pacientes com mucopolissacaridose. MÉTODOS: Estudo transversal e observacional de pacientes com mucopolissacaridose atendidos no ambulatório do Serviço de Genética Médica do Hospital de Clínicas de Porto Alegre. O critério de inclusão foi a existência de diagnóstico bioquímico ou molecular de qualquer tipo de mucopolissacaridose e a concordância em participar do estudo mediante assinatura do termo de consentimento livre e esclarecido. Foram avaliados 78 pacientes através de anamnese e exame físico fonoaudiológicos. RESULTADOS: Alterações em pelo menos um item de cada estrutura do sistema estomatognático ou função estomatognática foram encontradas em todos os pacientes que permitiram a avaliação de ambos estes itens do exame físico (n = 76/78). As estruturas e funções mais frequentemente comprometidas foram, respectivamente, a arcada dentária e a língua e a deglutição e a mastigação. A única diferença estatisticamente significativa encontrada entre os tipos de mucopolissacaridose envolveu a posição habitual da língua entre os dentes (mais frequente na mucopolissacaridose VI). Entre os pacientes com mucopolissacaridose I, II ou VI submetidos ou não à terapia de reposição enzimática, foi encontrada diferença estatisticamente significativa no modo oral de respiração (mais frequente no grupo sem terapia de reposição enzimática). CONCLUSÕES: Alterações dos sistemas e funções estomatognáticas são prevalentes em indivíduos com mucopolissacaridose, mesmo na vigência de terapia de reposição enzimática. Tal achado sugere que o acompanhamento fonoterápico tenha papel importante no plano de tratamento desse grupo de doenças, hipótese que deve ser confirmada por estudos adicionais.

OBJECTIVE: To characterize the stomatognathic system and stomatognathic functions in patients with mucopolysaccharidosis. METHODS: Cross-sectional and observational study of patients with mucopolysaccharidosis seen at the outpatient clinic at the Medical Genetics Service of Hospital de Clínicas de Porto Alegre. The inclusion criteria were the existence of a biochemical or molecular diagnosis of any type of mucopolysaccharidosis and the agreement to participate in the study by signing an informed consent form. Seventy-eight patients were evaluated through phonoaudiological anamnesis and physical exam. RESULTS: Alterations in at least one item of each structure of the stomatognathic system or stomatognathic function were found in all patients who allowed evaluation of both items on physical examination (n = 76/78). The most frequently compromised structures and functions were respectively the dental arch and the tongue, swallowing and mastication. The only statistically significant difference found between types of mucopolysaccharidosis involved the habitual position of the tongue between the teeth (most frequent in mucopolysaccharidosis VI). Among patients with mucopolysaccharidosis I, II or VI who underwent enzyme replacement therapy or not, there was statistically significant difference in oral breathing mode (more frequent in the group without enzyme replacement therapy). CONCLUSIONS: Alterations in stomatognathic systems and functions are prevalent among individuals with mucopolysaccharidosis, even if enzyme replacement therapy is administered. Such finding suggests that speech therapy follow-up plays a major role in the treatment plan of this group of diseases; this hypothesis should be confirmed by additional studies.

Las mucopolisacaridosis / The mucopolysaccharidosis

Las mucopolisacaridosis (MPS) son errores innatos del metabolismo de los glicosaminoglicanos (GAG), que ocurren por déficit de alguna de las enzimas que degradan estas moléculas en los lisosomas. Esto conduce al depósito intralisosomal progresivo de GAG en diferentes tejidos, lo que explica el carácter multistémico de estas patologías. Las MPS, se presentan con una frecuencia aproximada de 1 caso en 10.000 a 25.000 recién nacidos vivos y son de herencia autosómica recesiva, salvo la MPS II o enfermedad de Hunter, que se hereda ligada al cromosoma X. Las características clínicas más frecuentes de las MPS son la presencia de rasgos faciales toscos, macrocefalia, opacidades corneales, disostosis múltiple, talla baja, valvulopatía mitroaórtica, hepatoesplenomegalia, hernias umbilical e inguinales, con o sin retraso del desarrollo sicomotor y con un deterioro neurológico progresivo. Salvo para las formas menos severas de MPS I, hasta ahora no hay un tratamiento efectivo para estas patologías, por lo que el daño sistémico progresivo produce la muerte entre los fines de la primera y de la cuarta década de la vida. En esta revisión se discuten las características clínicas de las MPS con las particularidades de cada fenotipo, el modo de confirmar el diagnóstico y los avances recientes en su tratamiento.

Clinical and laboratorial study of 19 cases of mucopolysaccharidoses

The mucopolysaccharidoses (MPS) are a heterogeneous group of inborn errors of lysosomal glycosaminoglycan (GAG) metabolism. The importance of this group of disorders among the inborn errors of metabolism led us to report 19 cases. METHOD: We performed clinical, radiological, and biochemical evaluations of the suspected patients, which allowed us to establish a definite diagnosis in 19 cases. RESULTS: Not all patients showed increased GAG levels in urine; enzyme assays should be performed in all cases with strong clinical suspicion. The diagnosis was made on average at the age of 48 months, and the 19 MPS cases, after a full clinical, radiological, and biochemical study, were classified as follows: Hurler -- MPS I (1 case); Hunter -- MPS II (2 cases); Sanfilippo -- MPS III (2 cases); Morquio -- MPS IV (4 cases); Maroteaux-Lamy -- MPS VI (9 cases); and Sly -- MPS VII (1 case). DISCUSSION: The high relative frequency of Maroteaux-Lamy disease contrasts with most reports in the literature and could express a population variability

Clinical and laboratorial study of 19 cases of mucopolysaccharidoses.

UNLABELLED: The mucopolysaccharidoses (MPS) are a heterogeneous group of inborn errors of lysosomal glycosaminoglycan (GAG) metabolism. The importance of this group of disorders among the inborn errors of metabolism led us to report 19 cases. METHOD: We performed clinical, radiological, and biochemical evaluations of the suspected patients, which allowed us to establish a definite diagnosis in 19 cases. RESULTS: Not all patients showed increased GAG levels in urine; enzyme assays should be performed in all cases with strong clinical suspicion. The diagnosis was made on average at the age of 48 months, and the 19 MPS cases, after a full clinical, radiological, and biochemical study, were classified as follows: Hurler - MPS I (1 case); Hunter - MPS II (2 cases); Sanfilippo - MPS III (2 cases); Morquio - MPS IV (4 cases); Maroteaux-Lamy - MPS VI (9 cases); and Sly - MPS VII (1 case). DISCUSSION: The high relative frequency of Maroteaux-Lamy disease contrasts with most reports in the literature and could express a population variability.