Long-Term Cardiorespiratory, Endocrine, Ophthalmic, and Functional Outcomes in Adult Patients with Mucopolysaccharidosis Type I (Hurler Syndrome) Post Haematopoietic Stem Cell Transplantation: The Irish Experience

Abstract Mucopolysaccharidosis type IH (MPS IH) is caused by homozygous IDUA gene pathogenic variants. This results in deficiency of the enzyme α-L-iduronidase (IDUA), which is necessary for the degradation of glycosaminoglycans (GAGs). This study outlines the long-term outcomes in adult Irish patients affected with MPS IH, who were followed up for mean 28 years post Haematopoietic Stem Cell Transplantation. Nineteen adult MPS IH patients underwent HSCT in childhood. The participant cohort represents 6 families. Among the 13 patients with Irish Traveller ethnicity, 6 patients were either siblings or first cousins. All these related patients were homozygous for p. Trp402Ter (W402X). Mean age at the first transplantation was 8 months (range 3-21). Five patients had undergone a second transplantation (n=5, 26%) in childhood, due to graft failure. None of the patients had a cardiac valve surgery at the time of the study. 14/19 patients had mild to moderate aortic or mitral valve insufficiency or stenosis. 3/19 patients used non-invasive ventilation at night. Two patients had tracheostomy in situ. Both sensorineural as well as conductive hearing defects. No corneal clouding post corneal transplantation (n=8) was observed. Six patients attended regular secondary school. Multidisciplinary follow-up is needed to address the disease specific complications in adulthood.

Brain and visceral gene editing of mucopolysaccharidosis I mice by nasal delivery of the CRISPR/Cas9 system.

BACKGROUND: Mucopolysaccharidosis type I (MPS I) is an inherited disease caused by deficiency of the enzyme alpha-l-iduronidase (IDUA). MPS I affects several tissues, including the brain, leading to cognitive impairment in the severe form of the disease. Currently available treatments do not reach the brain. Therefore, in this study, we performed nasal administration (NA) of liposomal complexes carrying two plasmids encoding for the CRISPR/Cas9 system and for the IDUA gene targeting the ROSA26 locus, aiming at brain delivery in MPS I mice. METHODS: Liposomes were prepared by microfluidization, and the plasmids were complexed to the formulations by adsorption. Physicochemical characterization of the formulations and complexes, in vitro permeation, and mucoadhesion in porcine nasal mucosa (PNM) were assessed. We performed NA repeatedly for 30 days in young MPS I mice, which were euthanized at 6 months of age after performing behavioral tasks, and biochemical and molecular aspects were evaluated. RESULTS: Monodisperse mucoadhesive complexes around 110 nm, which are able to efficiently permeate the PNM. In animals, the treatment led to a modest increase in IDUA activity in the lung, heart, and brain areas, with reduction of glycosaminoglycan (GAG) levels in serum, urine, tissues, and brain cortex. Furthermore, treated mice showed improvement in behavioral tests, suggesting prevention of the cognitive damage. CONCLUSION: Nonviral gene editing performed through nasal route represents a potential therapeutic alternative for the somatic and neurologic symptoms of MPS I and possibly for other neurological disorders.

Mucopolysaccharidosis Type I.

Mucopolysaccharidosis type I (MPS I) is caused by the deficiency of α-l-iduronidase, leading to the storage of dermatan and heparan sulfate. There is a broad phenotypical spectrum with the presence or absence of neurological impairment. The classical form is known as Hurler syndrome, the intermediate form as Hurler-Scheie, and the most attenuated form is known as Scheie syndrome. Phenotype seems to be largely influenced by genotype. Patients usually develop several somatic symptoms such as abdominal hernias, extensive dermal melanocytosis, thoracolumbar kyphosis odontoid dysplasia, arthropathy, coxa valga and genu valgum, coarse facial features, respiratory and cardiac impairment. The diagnosis is based on the quantification of α-l-iduronidase coupled with glycosaminoglycan analysis and gene sequencing. Guidelines for treatment recommend hematopoietic stem cell transplantation for young Hurler patients (usually at less than 30 months of age). Intravenous enzyme replacement is approved and is the standard of care for attenuated-Hurler-Scheie and Scheie-forms (without cognitive impairment) and for the late-diagnosed severe-Hurler-cases. Intrathecal enzyme replacement therapy is under evaluation, but it seems to be safe and effective. Other therapeutic approaches such as gene therapy, gene editing, stop codon read through, and therapy with small molecules are under development. Newborn screening is now allowing the early identification of MPS I patients, who can then be treated within their first days of life, potentially leading to a dramatic change in the disease's progression. Supportive care is very important to improve quality of life and might include several surgeries throughout the life course.

CRISPR-Cas9-mediated gene editing in human MPS I fibroblasts.

Mucopolysaccharidosis type I (MPS I) is a lysosomal storage disorder (LSD). It is caused by mutations in the IDUA gene, which lead to the accumulation of the glycosaminoglycans dermatan and heparan sulfate. The CRISPR-Cas9 system is a new and powerful tool that allows gene editing at precise points of the genome, resulting in gene correction through the introduction and genomic integration of a wildtype sequence. In this study, we used the CRISPR-Cas9 genome editing technology to correct in vitro the most common mutation causing MPS I. Human fibroblasts homozygous for p.Trp402* (legacy name W402X) were transfected and analyzed for up to one month after treatment. IDUA activity was significantly increased, lysosomal mass was decreased, and next generation sequencing confirmed that a percentage of cells carried the wildtype sequence. As a proof of concept, this study demonstrates that CRISPR-Cas9 genome editing may be used to correct causative mutations in MPS I. LIST OF ABBREVIATIONS.

Immune tolerance induction for laronidase treatment in mucopolysaccharidosis I.

Enzyme replacement therapy (ERT) can produce anti-drug antibody (ADA) responses that reduce efficacy or lead to hypersensitivity reactions. Six patients with severe mucopolysaccharidosis type I (MPS I/Hurler syndrome) who did not receive hematopoietic stem cell transplantation underwent an immunosuppression regimen prior to initiating ERT with laronidase. The primary endpoint for immune tolerance induction was the number of patients with an ADA titer ≤ 3200 after 24 weeks of laronidase at the labeled dose. Cyclosporine levels were measured weekly and doses adjusted to maintain trough levels above 400 mg/mL. A 6-week (Cohort 1) or 12-week (Cohort 2) immune tolerance induction period with cyclosporine (initial dose: 15 or 20 mg/kg/day), azathioprine (initial dose: 2.5 or 5 mg/kg/day) and low-dose laronidase infusions (0.058-0.29 mg/kg/week) was followed by an immune-challenge period with laronidase infusions at the labeled dose (0.58 mg/kg/week) for 24 weeks. Anti-laronidase IgG titers were determined following treatment. There were 147 treatment-emergent adverse events reported, most of which were mild and not related to the study treatment. While there was no evidence of immune tolerance in 3 of 3 patients in Cohort 1, there were some indications of immune tolerance induction in 2 of 3 patients in Cohort 2. Patients with lower ADA titers showed greater reductions in urinary glycosaminoglycan excretion. Routine monitoring of plasma cyclosporine parent-compound levels by high pressure liquid chromatography proved difficult for clinical practice. The evolving clinical management of MPS I and a better understanding of the clinical impact of laronidase-related immunogenicity require reassessment of immune modulation strategies in patients with MPS I receiving laronidase treatment. CLINICAL TRIAL REGISTRATION: NCT00741338.

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.

Mucopolisacaridosis (síndrome de Hunter) / Mucopolysaccharidosis (Hunter syndrome)

Se realiza una presentación de un caso interesante, no comúnmente visto en la práctica médica, de unos de los tipos de mucopolisacaridosis, específicamente de un síndrome de Hunter. Se hace esta presentación con el objetivo de dar a conocer a estudiantes y profesionales de la salud, mediante fotos, las características físicas del paciente con dicho sídrome, quien llegó desnutrido al hospital; se le operó de la hernia umbilical y se mejoró su estado nutricional al compensarse su hepatopatía. Se le da el alta médica en mejores condiciones(AU)

We present here an interesting case of mucopolysaccharidoses, which is not commonly seen in medical practice, specifically a Hunter syndrome. This presentation is done in order to make known to students and health professionals, through photos, the physical characteristics of the patient with such syndrome. This patient arrived malnourished at the hospital, he was operated on the umbilical hernia and improved his nutritional status by compensating for his liver disease. This patient had medical discharge in better conditions(AU)

[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.

Mucopolisacaridosis de tipo I Hurler: Informe de un caso / Mucopolysaccharidosis I, Hurler syndrome: A case report

La mucopolisacaridosis de tipo I (MPS I), es una enfermedad genética autosómica recesiva de origen lisosomal, caracterizada por la deficiencia de la enzima a-L-iduronidasa. La deficiencia en el catabolismo de los glucosaminoglucanos resulta en su acumulación en diferentes tejidos y órganos. La incidencia global de la MPS I es de 0,99-1,99/100 000 nacidos vivos. Existen tres presentaciones clínicas: Hurler (grave), Hurler-Scheie (moderada) y Scheie (leve). Presentamos el caso de un niño de 10 años de edad a quien se le diagnosticó MPS I, de variedad grave en el año 2006, mediante medición de la actividad enzimática de a-L-iduronidasa en leucocitos. Este caso es el único con diagnóstico confirmado y tratamiento enzimático hasta el momento, en el Perú. Presenta infecciones respiratorias recurrentes, hernia umbilical, opacidad corneal, rasgos toscos, macroglosia, hipoacusia, rigidez articular, estenosis de la válvula pulmonar leve-moderada, manos en garra, retardo mental y retraso del crecimiento. Recibe terapia de reemplazo enzimático desde el año 2008, mostrando mejoría de los síntomas viscerales, más no del daño neurológico.(AU)

Mucopolysaccharidosis I (MPS I) is a rare, recessively inherited, lysosomal storage disorder caused by deficiency on the enzyme a-L-iduronidase. This defect results in accumulation of heparan and dermatan sulfate in different tissues and organs due to a deficiency in the catabolism of glycosaminoglycans. The overall incidence of MPS I is 0.99-1.99/100.000 live births. There are three clinical presentations: Hurler (severe), Hurler Scheie (mild) and Scheie (mild). We report the case of a 10-years-old male patient diagnosed with Hurler syndrome, the severe presentation, 5 years ago by enzyme a-L-iduronidase activity measurement in leukocytes; with a history of recurrent respiratory infections, umbilical hernia, corneal opacity, coarse facial features, macroglossia, hearing loss, stiffness of joints, cardiac compromise, claw hands, mental retardation and stunted growth. After enzyme replacement therapy the patient has shown improvement of visceral symptoms, but the neurological damage continuous in progress.(AU)

Mucopolisacaridosis de tipo I Hurler: Informe de un caso / Mucopolysaccharidosis I, Hurler syndrome: A case report

La mucopolisacaridosis de tipo I (MPS I), es una enfermedad genética autosómica recesiva de origen lisosomal, caracterizada por la deficiencia de la enzima a-L-iduronidasa. La deficiencia en el catabolismo de los glucosaminoglucanos resulta en su acumulación en diferentes tejidos y órganos. La incidencia global de la MPS I es de 0,99-1,99/100 000 nacidos vivos. Existen tres presentaciones clínicas: Hurler (grave), Hurler-Scheie (moderada) y Scheie (leve). Presentamos el caso de un niño de 10 años de edad a quien se le diagnosticó MPS I, de variedad grave en el año 2006, mediante medición de la actividad enzimática de a-L-iduronidasa en leucocitos. Este caso es el único con diagnóstico confirmado y tratamiento enzimático hasta el momento, en el Perú. Presenta infecciones respiratorias recurrentes, hernia umbilical, opacidad corneal, rasgos toscos, macroglosia, hipoacusia, rigidez articular, estenosis de la válvula pulmonar leve-moderada, manos en garra, retardo mental y retraso del crecimiento. Recibe terapia de reemplazo enzimático desde el año 2008, mostrando mejoría de los síntomas viscerales, más no del daño neurológico.

Mucopolysaccharidosis I (MPS I) is a rare, recessively inherited, lysosomal storage disorder caused by deficiency on the enzyme a-L-iduronidase. This defect results in accumulation of heparan and dermatan sulfate in different tissues and organs due to a deficiency in the catabolism of glycosaminoglycans. The overall incidence of MPS I is 0.99-1.99/100.000 live births. There are three clinical presentations: Hurler (severe), Hurler Scheie (mild) and Scheie (mild). We report the case of a 10-years-old male patient diagnosed with Hurler syndrome, the severe presentation, 5 years ago by enzyme a-L-iduronidase activity measurement in leukocytes; with a history of recurrent respiratory infections, umbilical hernia, corneal opacity, coarse facial features, macroglossia, hearing loss, stiffness of joints, cardiac compromise, claw hands, mental retardation and stunted growth. After enzyme replacement therapy the patient has shown improvement of visceral symptoms, but the neurological damage continuous in progress.

Oral findings in patients with mucolipidosis type III

Mucolipidosis type III is a rare, autosomal recessive disorder, which is part of a group of storage diseases as a result of inborn error of lysosomal enzyme metabolism. It is characterized by the gradual onset of signs and symptoms affecting the physical and mental development as well as visual changes, heart, skeletal and joint. Although oral findings associated with mucolipidosis type II have been extensively reported, there is a shortage of information on mucolipidosis type III. This paper presents radiological and histological findings of multiple radiolucent lesions associated with impacted teeth in the jaw of a 16 year-old youngster with mucolipidosis type III.

A mucolipidose tipo III é uma doença rara, autossômica recessiva, que faz parte de um grupo de doenças de depósito, decorrentes do erro inato do metabolismo das enzimas lisossômicas. Caracteriza-se pelo aparecimento progressivo de sinais e sintomas com repercussão no desenvolvimento físico e mental, bem como alterações visuais, cardíacas, esqueléticas e articulares. Apesar de achados bucais estarem bem relatados em associação à mucolipidose tipo II, esse artigo descreve achados radiográficos e histológicos de múltiplas lesões radiolúcidas, associadas a dentes inclusos nos maxilares, em uma jovem de 16 anos de idade com mucolipidose tipo III.

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.

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.