The clinical and genotypic-phenotypic findings of mucopolysaccharidosis VI patients: an Iraqi single-study descriptive study.

Background: Maroteaux-Lamy syndrome (mucopolysaccharidosis type VI; MPS VI) is a chronic illness that causes progressive enlargement, inflammation, or scarring of several tissues and organs until their collapse. In most cases, an infant with MPS VI shows no symptoms. The early signs and symptoms of MPS VI in children often develop in the first few months of life. MPS VI affects various systems in the body, including the skeletal, cardiac, and respiratory systems. The authors aim in our study to describe the clinical and genotypic-phenotypic findings of MPS VI patients in 'children Welfare Teaching Hospital, Medical City Complex.' Methods: The single-center study was conducted at the 'children Welfare Teaching Hospital, Medical City Complex' from November 2016 to May 2022. The research recruited 72 MPS VI patients from Iraq, all under 20. The authors investigated the sociodemographic characteristics, hematological lab results, gene-phenotype findings, and clinical features and evaluated the severity and progression of the MPS 6 disease. Results: Seventy-two Iraqi MPS VI patients were involved in the study, and the average age of the study sample was 6.38±3.4 (0.3-19). The consanguinity rate was 94.4%. In the research, females comprised 56.9% of the patients, and the Z-scores for body mass index and occipital-frontal head circumference were -2.66 and 1.2. The fascial features at diagnosis, 'coarse facies' (90.3%), dysostosis multiplex (93%), short stature (94.4%), and recurrent respiratory infections (91.6%), were the most common clinical features among the enrolled patients. The most frequent mutation was (complementary DNA: c.753C>G, protein effect: p.(Tyr2*) or p.(Tyr251Term), and the codon cross-tabulation: premature stop codon, or homozygous stop nonsense mutation/exon N.3) (33/69 (47.82%)). Furthermore, a statistically significant correlation existed between lower weight and height readings and the progressed and severe stages of the MPS VI illness. Conclusion: As the first research in Iraq with a sufficient sample size of MPS VI patients, the investigation presented important clinical and gene-phenotype findings and revealed the necessity for enhancing the diagnosis of MPS VI, including the updated molecular analysis and monitoring the multisystem parameters, aberrant comorbidities, and the progression and severity.

Visual impairment in mucopolysaccharidosis VI.

Mucopolysaccharidosis (MPS) VI is a rare genetic disease characterized by deficient activity of N-acetylgalactosamine 4-sulfatase, leading to the systemic deposition of glycosaminoglycans. Ocular involvement is classically characterized by progressive corneal clouding, ocular hypertension (OHT), and optic neuropathy. Although corneal clouding can be solved with penetrating keratoplasty (PK), visual impairment usually remains, being frequently attributed to glaucoma. The purpose of this study was to retrospectively describe a series of MPS VI patients with optic neuropathy in order to deepen the knowledge regarding the causes of severe visual impairment among these patients. We present five genetically confirmed clinical cases of MPS VI, treated with enzymatic replacement therapy, and with regular systemic and ophthalmologic follow-up. Corneal clouding was a common early presenting feature, leading to PK in four patients. During their follow-up, all patients developed very low visual acuities regardless of corneal grafts outcomes and controlled intraocular pressure (IOP). Furthermore, all patients exhibited optic atrophy and imagiological evidence of significant subarachnoid space enlargement and consequent optic nerve thickness reduction, suggesting compression of the optic nerve in a retro-ocular location as the cause of optic neuropathy. Although optic neuropathy in MPS VI is commonly attributed to glaucoma due to OHT, by describing a series of five MPS VI patients, we provided evidence that, differently from glaucoma, compression of optic nerve in a retro-ocular location is crucial for the development of optic neuropathy, at least in some cases. We propose the denomination of posterior glaucoma and suggest it as an important cause of optic neuropathy, leading to severe visual impairment and blindness among these patients.

Surgical treatment of craniovertebral stenosis in two siblings with type vi mucopolysaccharidosis / Tratamento cirúrgico de estenose craneo-vertebral em dois irmãos com mucopolisacaredose tipo vi / Tratamiento quirúrgico de estenosis craneo-vertebral en dos hermanos con mucopolisacaridosis tipo vi

ABSTRACT We describe two cases of surgical treatment of craniovertebral stenosis in preschool-aged brothers with Maroteaux-Lamy (MPS type VI) syndrome. The older brother was diagnosed with MPS during her second pregnancy. Literature describing familial cases of the disease and the treatment strategy in young children with MPS type VI and spinal canal stenosis is scarce. Based on the presented observations, indications, surgical treatment approaches, and perioperative management of patients with mucopolysac-charidosis are suggested. MPS type VI may have familial forms of the disease and the course of craniovertebral stenosis is similar in siblings. Surgical treatment of craniovertebral stenosis in these patients should be performed timely. We adhere to the point of view of early treatment of craniovertebral stenosis in patients with MPS before irreversible spinal cord dysfunction develops. Level of Evidence IV; Prognostic Studies - Investigating the Effect of a Patient Characteristic on the Outcome of Disease and Case series.

Resumo: Descreve-se dois casos de tratamento cirúrgico de estenose craniovertebral entre irmãos em idade pré-escolar com síndrome de Maroteaux-Lamy (MPS tipo VI). O irmão mais velho foi diagnosticado com MPS durante a segunda gravidez. A literatura que descreve casos familiares da doença e a estratégia de tratamento em crianças pequenas com MPS tipo VI e estenose do canal raquidiano é escassa. Com base nas observações apresentadas, foram sugeridas indicações, abordagens de tratamento cirúrgico e manejo perioperatório de pacientes com mucopolissacaridose. A MPS tipo VI pode apresentar formas familiares da doença e o curso da estenose craniovertebral é semelhante entre irmãos. O tratamento cirúrgico da estenose craniovertebral nesses pacientes deve ser realizado em tempo hábil. Adere-se ao conceito de tratamento precoce da estenose craniovertebral em pacientes com MPS antes que se desenvolva uma disfunção irreversível da medula espinhal. Nível de Evidência IV; Estudos Prognósticos - Investigando o Efeito de uma Característica de Paciente sobre o Resultado de uma Doença e de uma Série de Casos.

Resumen: Se describen dos casos de tratamiento quirúrgico de estenosis craneovertebral en hermanos de edad preescolar con síndrome de Maroteaux-Lamy (MPS tipo VI). Al hermano mayor se le diagnosticó MPS durante el segundo embarazo. La bibliografía que expone casos familiares de la enfermedad y la estrategia de tratamiento en niños pequeños con MPS tipo VI y estenosis del tubo vertebral es escasa. Sobre el fundamento de las observaciones presentadas, se sugieren indicaciones, enfoques de tratamiento quirúrgico y manejo perioperatorio de pacientes con mucopolisacaridosis. La MPS tipo VI puede presentar formas familiares de la enfermedad y el curso de la estenosis craneovertebral es semejante en los hermanos. El tratamiento quirúrgico de la estenosis craneovertebral en estos pacientes debe realizarse tempranamente. Se adhiere al planteamiento del tratamiento precoz de la estenosis craneovertebral en pacientes con MPS anticipándose al desarrollo de una disfunción irreversible de la médula espinal. Nivel de Evidencia IV; Estudios Pronósticos - Investigando el Efecto de una Característica del Paciente en el Resultado de la Enfermedad y Series de Casos.

Mucopolysaccharidosis type VI (Maroteaux-Lamy syndrome): defining and measuring functional impacts in pediatric patients.

BACKGROUND: Research about pediatric patients' perspective on mucopolysaccharidosis type VI (MPS VI) and its impact on daily life is limited. We aimed to identify the disease concepts of interest that most impact function and day-to-day life of pediatric patients with MPS VI, and to consider clinical outcome assessments (COAs) that may potentially measure meaningful improvements in these concepts. METHODS: Potential focus group participants were identified by the National MPS Society (USA) and invited to participate if they self-reported a clinician-provided diagnosis of MPS VI and were 4 to 18 years, receiving enzyme replacement therapy (ERT), and available to attend a 1-day focus group with their caregiver in Dallas, TX, USA. The focus group consisted of a series of polling and open-ended concept elicitation questions and a cognitive debriefing session. The discussion was audio recorded, transcribed verbatim, and analyzed to identify disease concepts of interest and functional impacts most relevant to participants. RESULTS: Overall, caregivers (n = 9) and patients with MPS VI (n = 9) endorsed that although their children/they receive ERT, residual symptoms exist and impact health-related quality of life. The key disease concepts of interest identified were impaired mobility, upper extremity and fine motor deficits, pain, and fatigue. Pain was unanimously reported by all patients across many areas of the body and impacted daily activity. Key disease concepts were mapped to a selection of pediatric COAs including generic measures such as PROMIS®, PODCI, CHAQ, and PedsQL™. Caregivers endorsed the relevance of PODCI and PROMIS Upper Extremity, Mobility, and Pain items and all patients completed the NIH Toolbox Pegboard Dexterity Test. Additional COAs that aligned with the disease concepts included range of motion, the 2- and 6-min walk tests, timed stair climbs, Bruininks-Oseretsky Test of Motor Proficiency, 2nd edition, grip strength, pain visual analog scale, and the Faces Pain Scale-Revised. CONCLUSION: An MPS VI focus group of pediatric patients and their caregivers identified impaired mobility, upper extremity and fine motor deficits, pain, and fatigue as key disease concepts of interest. These disease concepts were mapped to existing pediatric COAs, which were provided to the group for endorsement of their relevance.

Clinical and event-based outcomes of patients with mucopolysaccharidosis VI receiving enzyme replacement therapy in Turkey: a case series.

BACKGROUND: The objective of this study was to describe clinical manifestations and events of patients with mucopolysaccharidosis (MPS) VI in Turkey who are treated with galsulfase enzyme replacement therapy (ERT). Clinical data of 14 children with MPS VI who were followed up at the Department of Pediatrics of the Gazi University Faculty of Medicine in Ankara, Turkey were retrospectively collected from the patients' medical records. Patients were selected based on availability of a pre-ERT baseline and follow-up clinical data for a similar period of time (1.9-3.2 years). Event data (occurrence of acute clinical events, onset of chronic events, surgeries) collected during hospital visits and telemedicine were available for up to 10 years after initiation of ERT (2.5-10 years). RESULTS: Age at initiation of ERT ranged from 2.8 to 15.8 years (mean age 7.5 years). All patients presented with reduced endurance and skeletal abnormalities (dysostosis multiplex) on radiography. Other common clinical manifestations were cardiac valve disease (N = 13), short stature (N = 11), cranial abnormalities on MRI (N = 10), spinal abnormalities on MRI (N = 7), and mild cognitive impairment (N = 6). School attendance was generally poor, and several patients had urinary incontinence. After 1.9 to 3.2 years of ERT, most patients showed improvements in endurance in the 6-min walk test and 3-min stair climb tests; the frequency of urinary incontinence decreased. ERT did not seem to prevent progression of cardiac valve disease, eye disorders, hearing loss, or bone disease. Long-term event-based data showed a high incidence of respiratory tract infections, adenotonsillectomy/adenoidectomy, reduced sleep quality, sleep apnea, and depression before initiation of ERT. The number of events tended to remain stable or decrease in all patients over 2.5-10 years follow-up. However, the nature of the events shifted over time, with a reduction in the frequency of respiratory tract infections and sleep problems and an increase in ophthalmologic events, ear tube insertions, and depression. CONCLUSIONS: This case series shows the high disease burden of the MPS VI population in Turkey and provides a unique insight into their clinical journey based on real-life clinical and event-based data collected before and after initiation of ERT.

Long-term impact of early initiation of enzyme replacement therapy in 34 MPS VI patients: A resurvey study.

Patients with mucopolysaccharidosis type VI (MPS VI) present with a wide range of disease severity and clinical manifestations, with significant functional impairment and shortened lifespan. Enzyme replacement therapy (ERT) with galsulfase has been shown to improve clinical and biochemical parameters including patient survival, quality of life and growth. The present study is a resurvey of 34 Brazilian MPS VI patients with rapidly progressive disease (classical phenotype) who initiated ERT with galsulfase under five years of age and had been on ERT until data collection in 2019, with few exceptions (n = 4 patients who died before 2019). Anthropometric measures, urinary glycosaminoglycans, and data regarding cardiac, orthopedic, neurologic, sleep apnea, hearing and ophthalmologic outcomes were filled in by specialists. Pubertal development, clinical complications, hospitalizations, and surgeries were also assessed. In this resurvey study, treatment with galsulfase has shown to be safe and well tolerated in MPS VI patients who initiated ERT under the age of 5 years and who have been undergoing ERT for approximately 10 years. Mortality rate suggests that early initiation of ERT may have a positive impact on patients' survival, improving but not preventing disease progression and death. MPS VI patients on ERT also showed improved growth velocity and the pubertal development was normal in all surviving patients. Follow-up data on pneumonia and hospitalization suggest that early ERT may have a protective effect against major respiratory complications. Cardiac valve disease progressed since their prior evaluation and spinal cord compression was observed in a large number of patients, suggesting that these disease complications were not modified by ERT.

Long-term outcomes of patients with mucopolysaccharidosis VI treated with galsulfase enzyme replacement therapy since infancy.

OBJECTIVE: Long-term outcomes of patients with mucopolysaccharidosis (MPS) VI treated with galsulfase enzyme replacement therapy (ERT) since infancy were evaluated. METHODS: The study was a multicenter, prospective evaluation using data from infants with MPS VI generated during a phase 4 study (ASB-008; Clinicaltrials.govNCT00299000) and clinical data collected ≥5 years after completion of the study. RESULTS: Parents of three subjects from ASB-008 (subjects 1, 2, and 4) provided written informed consent to participate in the follow-up study. One subject was excluded as consent was not provided. Subjects 1, 2, and 4 were aged 0.7, 0.3, and 1.1 years, respectively, at initiation of galsulfase and 10.5, 7.9, and 10.5 years, respectively, at follow-up. All subjects had classical MPS VI based on pre-treatment urinary glycosaminoglycans and the early onset of clinical manifestations. At follow-up, subject 4 had normal stature for age; subjects 1 and 2 had short stature, but height remained around the 90th percentile of growth curves for untreated classical MPS VI. Six-minute walk distance was normal for age/height in subjects 1 (550 m) and 4 (506 m), and reduced for subject 2 (340 m). Subject 2 preserved normal respiratory function, while percent predicted forced vital capacity and forced expiratory volume in 1 s decreased over time in the other subjects. Skeletal dysplasia was already apparent in all subjects at baseline and continued to progress. Cardiac valve disease showed mild progression in subject 1, mild improvement in subject 4, and remained trivial in subject 2. All subjects had considerably reduced pinch and grip strength at follow-up, but functional dexterity was relatively normal for age and there was limited impact on activities of daily living. Bruininks-Oseretsky Test of Motor Proficiency (BOT-2) results showed that subjects 2 and 4 had numerous fine and gross motor competencies. Corneal clouding progressed in all subjects, while progression of hearing impairment was variable. Liver size normalized from baseline in subjects 1 and 4, and remained normal in subject 2. CONCLUSION: Very early and continuous ERT appears to slow down the clinical course of MPS VI, as shown by preservation of endurance, functional dexterity, and several fine and gross motor competencies after 7.7-9.8 years of treatment, and less growth impairment or progression of cardiac disease than could be expected based on the patients' classical phenotype. ERT does not seem to prevent progression of skeletal or eye disease in the long term.

Knee and ankle disorders during functional gait in mucopolysaccharidosis type VI / Distúrbios articulares de joelho e tornozelo durante a marcha funcional na mucopolissacaridose tipo VI / Trastornos de la rodilla y el tobillo durante la marcha funcional en mucopolisacaridosis tipo VI

ABSTRACT To evaluate knee and ankle disorders during functional gait assessment in individuals with Mucopolysaccharidosis type VI (MPS VI). 19 subjects were included in this cross-sectional study and allocated in three groups according to age: Children Group (n=11); Adolescent Group (n=4); and Adult Group (n=4). Subphases of one gait cycle were analyzed: Initial contact; Medium support, and Pre-Balance. All volunteers with MPS VI presented greater knee and ankle flexion angles, in all gait subphases, when compared to the normal values defined by literature (p<0.05). Initial contact subphase: knee flexion angle ranging from 8.5º to 15º; Ankle = Child Group −23.73º ± 8.53º; Adolescent Group = −25º ± 11.22º; Adult Group = −27.75º ± 3.3º. Medium support subphase: Knee = Child Group 19.64º ± 10.47º; Adolescent Group 16.75º ± 10.34º; Adult Group = 21.25º ± 12.84º. Ankle = Child Group −18.82º ± 8.91º ± 8.53º; Adolescent Group = −16.5º ± 9.33º; Adult Group = −22.25º ± 4.19º. Pre-Balance subphase: Knee = Child Group 22.72º ± 13.49º; Adolescent Group 21.25º ± 7.97º; Adult Group = 27º ± 16.27º. Ankle = Child Group -15º ± 9.76º; Adolescent Group = −15.75º ± 5.31º; Adult Group = −14.75º ± 3.86º. In this study, MPS VI individuals presented hyperflexion of knee and ankle as the main joint disorders during functional gait, regardless of age.

RESUMO O objetivo deste estudo foi avaliar distúrbios articulares de joelho e tornozelo durante a marcha funcional na Mucopolissacaridose tipo VI (MPS VI). 19 indivíduos foram incluídos neste estudo transversal e alocados em três grupos de acordo com a idade: Grupo Crianças (n=11); Grupo Adolescentes (n=4); e Grupo Adultos (n=4). Foram analisadas as subfases de um ciclo da marcha: contato inicial; apoio médio e pré-balanço. Todos os voluntários com a MPS VI apresentaram maiores ângulos de flexão do joelho e tornozelo, em todas as subfases da marcha, quando comparados aos valores normais definidos pela literatura (p<0,05). Subfase contato inicial: ângulo de flexão do joelho variando de 8,5º a 15º; Tornozelo = Grupo Criança -23,73º ± 8,53º; Grupo Adolescente = -25º ± 11,22º; Grupo Adulto = -27,75º ± 3,3º. Subfase apoio médio: Joelho = Grupo Criança 19,64º ± 10,47º; Grupo Adolescente 16,75º ± 10,34º; Grupo Adulto = 21,25º ± 12,84º. Tornozelo = Grupo Criança -18,82º ± 8,91º ± 8,53º; Grupo Adolescente = -16,5º ± 9,33º; Grupo Adulto = -22,25º ± 4,19º. Subfase pré-balanço: Joelho = Grupo Criança 22,72º ± 13,49º; Grupo Adolescente 21,25º ± 7,97º; Grupo Adulto = 27º ± 16,27º. Tornozelo = Grupo Criança = -15º ± 9,76º; Grupo Adolescente = -15,75º ± 5,31º; Grupo Adulto = -14,75º ± 3,86º. Neste estudo, os indivíduos com MPS VI apresentaram hiperflexão do joelho e tornozelo como principais distúrbios articulares durante a marcha funcional, independentemente da idade.

RESUMEN El objetivo de este estudio fue evaluar los trastornos de la articulación de la rodilla y el tobillo durante la marcha funcional en mucopolisacaridosis tipo VI (MPS VI). En este estudio transversal participaron 19 personas, las cuales se asignaron a tres grupos según la edad: Grupo Niños (n=11); Grupo Adolescente (n=4); y Grupo Adulto (n=4). Se analizaron las subfases de un ciclo de marcha: contacto inicial; soporte mediano y balance previo. Todos los voluntarios con MPS VI tuvieron mayores ángulos de flexión de rodilla y tobillo en todas las subfases de la marcha en comparación con los valores normales definidos por la literatura (p<0,05). En la subfase de contacto inicial: ángulo de flexión de la rodilla varia de 8,5º a 15º; Tobillo = Grupo Niños -23,73º ± 8,53º; Grupo Adolescente = -25º ± 11,22º; Grupo Adulto = -27,75º ± 3,3º. En la subfase de soporte mediano: Rodilla = Grupo Niños 19,64º ± 10,47º; Grupo Adolescente 16,75º ± 10,34º; Grupo Adulto = 21,25º ± 12,84º. Tobillo = Grupo Niños -18,82º ± 8,91º ± 8,53º; Grupo Adolescente = -16,5º ± 9,33º; Grupo Adulto = -22,25º ± 4,19º. En la subfase de balance previo: Rodilla = Grupo Niños 22,72º ± 13,49º; Grupo Adolescente 21,25º ± 7,97º; Grupo Adulto = 27º ± 16,27º. Tobillo = Grupo Niños = -15º ± 9,76º; Grupo Adolescente = -15,75º ± 5,31º; Grupo Adulto = -14,75º ± 3,86º. En este estudio, los individuos con MPS VI presentaron hiperflexión de rodilla y tobillo como los principales trastornos articulares durante la marcha funcional independiente de la edad.

Clinical ocular manifestations of Taiwanese patients with mucopolysaccharidoses VI (Maroteaux-Lamy syndrome).

Mucopolysaccharidoses (MPS) is a group of lysosomal storage disorders that lead to accumulation of glycosaminoglycans (GAGs) in many tissues and organs, resulting in different clinical features. In this study, we conducted the manifestation changes of refractive error, corneal clouding, and intraocular pressure in two Taiwanese MPS VI patients with enzyme replacement therapy (ERT) initiated at the age of eight. In case 1, hyperopia was noted before and after ERT. Clinical observation showed no significant improvement in corneal clouding after ERT. In case 2, hyperopia was also noted initially before ERT and unable to be measured due to severe corneal opacity. Clinical observation showed no significant improvement in corneal clouding in after ERT, and the best-corrected visual acuity worsen and keratoplasty was needed in both eyes. Case 2 also had ocular hypertension and suspect MPS VI-related. However, due to severe corneal clouding, optic disc changes were hard to examine, and visual field was unable to be tested. Although some literature shows that ERT may be effective in preventing and/or clearing corneal stromal GAGs, accumulation and the timing of treatment initiation cloud be a clinical prognosis predictor; in this experience, no significant improvement of corneal clouding was observed in patients with MPS IV after ERT. Hyperopia and glaucoma were noted, and showed no changes after ERT. Severe corneal clouding can lead to difficulties in diagnosis and monitoring of hyperopia and glaucoma.

Enzyme replacement therapy initiated in adulthood: Findings from the mucopolysaccharidosis VI Clinical Surveillance Program.

OBJECTIVE: To evaluate the impact of galsulfase enzyme replacement therapy (ERT) when initiated in adulthood for patients with mucopolysaccharidosis (MPS) VI. METHODS: In 2005, the multi-national, MPS VI Clinical Surveillance Program (CSP) was established to collect long-term observational data from routine clinical and laboratory assessments. A sub-analysis was performed in patients who started ERT at ≥16 years of age and had received galsulfase for ≥6 months. Urinary glycosaminoglycans (uGAG), 6-min walk test (6MWT), 3-min stair climb test (3MSCT), pulmonary function measures, cardiac function, ophthalmology measures, liver and spleen sizes, and safety were evaluated. RESULTS: Of 223 patients enrolled in the CSP, 51 were included in the sub-analysis. Patients were between 16 and 63 years of age at first infusion. From pre-treatment baseline, uGAG level decreased by a mean (±standard deviation [SD]) of 66 (±45)% (N = 29) after a median follow-up of 7.2 years. 6MWT distance decreased slightly by a mean of 17 (±107) meters (N = 23) after 6.6 years. Stairs/min in the 3MSCT increased by a mean of 26 (±33) (N = 14) after 2.8 years. Pulmonary function measures, forced expiratory volume in 1 second and forced vital capacity, increased by a mean of 0.06 (±0.21) L after 7.3 years and 0.05 (±0.28) L after 7.2 years, respectively (N = 19 for both measures). Overall, galsulfase was well tolerated, with most adverse events reported being MPS-related clinical manifestations and not related to galsulfase. CONCLUSIONS: Results of this sub-analysis of the CSP suggest that initiation of galsulfase in adulthood is well tolerated and can possibly stabilize MPS VI in the long term.

Identification of arylsulfatase B gene mutations and clinical presentations of Iranian patients with Mucopolysaccharidosis VI.

BACKGROUND: Mucopolysaccharidosis (MPS) type VI, also known as Maroteaux-Lamy syndrome, is an autosomal recessive lysosomal storage disorder caused by a deficiency in arylsulfatase B (ARSB) enzyme. Our objectives were to investigate clinical phenotypes and performed molecular studies in Iranian patients with MPS VI, for the first time, in the southwestern Iran. METHODS: We studied 14 cases from 10 unrelated kindreds with MPS VI that were enrolled during 8 years. The mutational analysis of coding and flanking regions of ARSB gene was performed for the patients and their families using genomic DNA from whole blood by direct sequencing. RESULTS: All cases had parental consanguinity. Except one who had Fars ethnicity and presented with a very mild degree of coarse face, but normal otherwise, even near normal height, all were from Arab ethnicity with characteristic phenotypes including severe facial changes, cardiac involvement and dysostosis multiplex. Sequencing analysis of ARSB gene revealed four pathogenic homozygote mutations, including a novel nonsense mutation c.281C>A (p.Ser94X) in 9 patients, as well as, a known nonsense mutation c.753C>G (p.Try251X) in 3 cases, and two missense mutations c.904G>A (p.Gly302Arg) and c.454C>T (p.Arg152Trp) in two cases. The type of mutations affected the severity patient's phenotypes. CONCLUSIONS: These findings increased the genetic databases of Iranian patients with MPS VI and would be so much helpful for the high-risk families to speed the detection of carriers with accuracy and perform the prenatal test of disorder with cost-effective in this population.

Enzyme replacement therapy outcomes across the disease spectrum: Findings from the mucopolysaccharidosis VI Clinical Surveillance Program.

The impact of galsulfase enzyme replacement therapy in patients with mucopolysaccharidosis (MPS) VI with phenotypes at either end of the disease spectrum was evaluated. The MPS VI Clinical Surveillance Program (CSP) was established to collect long-term observational data from routine clinical and laboratory assessments. A subanalysis of the CSP was performed in patients with pretreatment urinary glycosaminoglycan (uGAG) levels <100 µg/mg and ≥200 µg/mg creatinine (low- and high-uGAG) who had received galsulfase for ≥6 months. uGAG, 6-minute walk test (6MWT), 3-minute stair climb test (3MSCT), pulmonary function measures, height/growth, cardiac function, and safety were evaluated. Patients with a high-uGAG level at pre-treatment baseline (N = 68) showed greater impairments in endurance and pulmonary function than those with low-baseline uGAG levels (N = 39). From pre-treatment baseline, the distance walked on the 6MWT in the low- and high-uGAG groups increased by a mean (±SD) of 49 (±151) meters and 42 (±165) meters (median follow-up 5.5 and 7.7 years), respectively. The number of stairs/min climbed in the 3MSCT in the low- and high-uGAG groups increased by a mean of 18 (±33) and 30 (±45) (median follow-up 2.8 and 3.5 years), respectively. Overall, pulmonary function remained unchanged for both groups. No impact was seen on cardiac function. Galsulfase was generally well tolerated in both groups, with most adverse events being MPS-related complications unrelated to galsulfase. Results of this CSP sub-analysis suggest that galsulfase stabilizes MPS VI in the long-term and has an acceptable safety profile, regardless of baseline disease severity.

Liver transplantation: New treatment for mucopolysaccharidosis type VI in rats.

BACKGROUND: Mucopolysaccharidosis (MPS) VI is a rare, autosomal recessive congenital metabolic disorder caused by deficient activity of the lysosomal metabolic enzyme, N-acetylgalactosamine 4-sulfatase. Enzyme replacement therapy (ERT) is the current treatment for MPS VI, although it involves limited compliance to the therapy and high cost. The aim of this study was to develop a new method of treatment by conducting an orthotopic liver transplantation (LTx) using an animal model of human MPS VI, and to evaluate and examine its effectiveness for treating MPS VI. METHODS: LTx was carried out from normal unaffected to affected MPS VI rats (MPR), which were then killed after LTx, and tissues from the heart, spleen, and knee joint, as well as serum, collected for biological and morphologic evaluation. RESULTS: Liver-transplanted (LTx) MPR had the same level of N-acetylgalactosamine 4-sulfatase activity in the liver and lungs as normal unaffected MPR, and the urinary secretion of mucopolysaccharides/glycosaminoglycan (GAG) in LTx MPR was significantly decreased. Furthermore, on histopathology, the spleens of LTx MPR showed elimination of vacuole cells. In the knee joints, growth plates became thinner, and on radiography the facial and cranial bones of LTx MPR were morphologically normal. CONCLUSIONS: LTx from normal to affected MPR was effective for symptoms of MPS and accumulation of GAG, suggesting that LTx could be a promising alternative approach for MPS VI.

Mutational analysis of ARSB gene in mucopolysaccharidosis type VI: identification of three novel mutations in Iranian patients.

OBJECTIVES: Mucopolysaccharidosis VI (MPS VI) or Maroteaux-Lamy syndrome is a rare metabolic disorder, resulting from the deficient activity of the lysosomal enzyme arylsulfatase B (ARSB). The enzymatic defect of ARSB leads to progressive lysosomal storage disorder and accumulation of glycosaminoglycan (GAG) dermatan sulfate (DS), which causes harmful effects on various organs and tissues and short stature. To date, more than 160 different mutations have been reported in the ARSB gene. MATERIALS AND METHODS: Here, we analyzed 4 Iranian and 2 Afghan patients, with dysmorphism indicating MPS VI from North-east Iran. To validate the patients' type of MPS VI, urine mucopolysaccharide and leukocyte ARSB activity were determined. Meanwhile, genomic DNA was amplified for all 8 exons and flanking intron sequences of the ARSB gene to analyze the spectrum of mutations responsible for the disorder in all patients. RESULTS: Abnormal excretion of DS and low leukocyte ARSB activity were observed in the urine samples of all 6 studied patients. In direct DNA sequencing, we detected four different homozygous mutations in different exons, three of which seem not to have been reported previously: p.H178N, p.H242R, and p.*534W. All three novel substitutions were found in patients with Iranian breed. We further detected the IVS5+2T>C mutation in Afghan siblings and four different homozygous polymorphisms, which have all been observed in other populations. CONCLUSION: results indicated that missense mutations were the most common mutations in the ARSB gene, most of them being distributed throughout the ARSB gene and restricted to individual families, reflecting consanguineous marriages.

Maroteaux-Lamy syndrome: a rare and challenging case of mitral valve replacement.

Maroteaux-Lamy syndrome is a very rare multisystem disorder. Cardiac valve surgery is common in these patients who present a unique set of perioperative and intraoperative challenges to the surgeon and treating team. We describe successful mitral valve replacement using an inverted aortic prosthesis in a 29-year-old lady with Maroteaux-Lamy syndrome, with a good result at 10 months.

Avaliação do equilí­brio e risco de queda em pacientes com mucopolissacaridose VI / Evaluation of balance and risk of falls in patients with mucopolysaccharidosis VI

Introdução: A Mucopolissacaridose VI é uma doença rara, hereditária, com mutação no gene ARSB, que provoca complicações multissistêmicas com deformidades osteomusculares que podem dificultar o equilí­brio estático e dinâmico. Objetivo: Avaliar o equilí­brio e o risco de queda em pacientes com Mucopolissacaridose VI (MPS VI). Métodos: Trata-se de um estudo observacional descritivo transversal, do tipo série de casos, realizado na Associação Pernambucana de Mucopolissacaridoses, cuja amostra foi constituí­da por 5 pacientes que recebem tratamento fisioterapêutico no local, de ambos os gêneros, com faixa etária de 6 a 39 anos, e diagnóstico de MPS VI. Foi utilizada uma ficha de avaliação fisioterapêutica elaborada pelas pesquisadoras para avaliar aspectos sociodemográficos e clí­nicos dos pacientes e em seguida, foi aplicado o Índice de Tinetti. Os dados foram apresentados através de tabelas e figuras, contendo as frequências absoluta e relativa, média e desvio-padrão ou mediana e intervalo interquartil. Resultados: Dos casos estudados, a idade média foi de 11 anos, 60% eram do sexo masculino, todos os avaliados apresentaram baixa estatura, com altura média de 115,0 cm e diferença média de 0,5 cm entre a altura dos membros inferiores, além de reduzidas pontuações no Índice de Tinetti, com 80% apresentando alto risco de quedas e 20% apresentando moderado risco de quedas. Conclusão: Foi possí­vel evidenciar o impacto negativo das alterações osteomioarticulares da MPS VI no equilí­brio estático e dinâmico e na marcha dos portadores, além do importante risco de quedas. (AU)

Introduction: Mucopolysaccharidosis VI is a rare hereditary disease with a mutation in the ARSB gene that causes multisystemic complications with musculoskeletal deformities that may hamper static and dynamic balance. Objective: To evaluate the balance and risk of falls in patients with Mucopolysaccharidosis VI (MPS VI). Methods: This is a cross-sectional, observational descriptive, case-series study conducted at the Association of Mucopolysaccharidoses of Pernambuco/Brazil - AMPS, whose sample consisted of 5 patients receiving on-site physiotherapeutic treatment of both genders, aged 6 to 39 years, with diagnosis of MPS VI. A physiotherapeutic evaluation sheet was elaborated by the researchers to evaluate the sociodemographic and clinical aspects of the patients, followed by the Tinetti Index. Data were presented through tables and figures, containing the absolute and relative frequencies, mean and standard deviation, or median and interquartile range. Results: Of the cases studied, the mean age was 11 years, 60% were males, all of them presented a short stature, with a mean height of 115.0 cm and a mean difference of 0.5 cm between the height of the lower limbs , in addition to reduced scores in the Tinetti Index, with 80% presenting a high risk of falls and 20% presenting moderate risk of falls. Conclusion: It was possible to show the negative impact of MPS VI osteomyoarticular changes in the static and dynamic balance and gait of the patients, besides the important risk of falls. (AU)

Level of independence, functional capacity and respiratory muscle strength of patients with mucopolysaccharidosis type VI in the Northeast of Brazil / Nível de independência, capacidade funcional e força muscular respiratória de pacientes com mucopolissacaridose tipo VI no Nordeste do Brasil

Abstract Objectives: to assess the functional independence, functional capacity and respiratory muscle strength (RMS) in individuals with mucopolysaccharidosis (MPS) type VI. Methods: in this cross-sectional study, the Pediatric Evaluation of Disability Inventory (PEDI) and the Functional Independence Measure (FIM) scales were used to assess the functional independence. The functional capacity and the RMS were assessed by a 6-minute walk test (6MWT) and Manovacuometry, respectively. The associations between RMS and 6MWD were analyzed by using the adjusted simple linear regression models. And besides, the T-test was used to compare the differences among the groups. Results: twenty-four patients with MPS VI were included, the median age was 8 (ranged from 2-38 years old). The PEDI presented a functional performance below the expectations at the self-care and mobility domains of 33.3% when compared to groups of Brazilian children at the same age assessed with typical development. The decreased social function was found in only one single case. According to the FIM, of the 12 patients evaluated (age> 7.5 years), 58.3% were classified as modified dependence and 41.7% as modified independence. The mean distance in the 6MWT was significantly lower than predicted, 263m in G1 (children, n= 7) and 336m in G2 (adolescents and adults, n=6), p<0.001. The RMS was also lower than predicted in both groups, except for the RMS in G1. Conclusions: the functional capacity and the RMS were significantly reduced in individuals with MPS VI, with a decreased functional independence in one-third of the patients. However, a multidisciplinary follow-up in this population is essential to prevent, diagnose and treat early complications.

Resumo Objetivos: avaliar a independência funcional, capacidade funcional e força muscular respiratória (FMR) em indivíduos com mucopolissacaridose (MPS) tipo VI. Métodos: neste estudo transversal, as escalas Inventário de Avaliação Pediátrica de Incapacidade (PEDI) e Medida de Independência Funcional (MIF) foram utilizadas para avaliar a independência funcional. A capacidade funcional e a FMR foram avaliadas por teste de caminhada de 6 minutos (6MWT) e Manovacuometria, respectivamente. As associações entre FMR e 6MWD foram analisadas usando modelos de regressão linear simples. Além disso, t-test foi usado para comparar diferenças entre grupos. Resultados: vinte e quatro pacientes com MPS VI foram incluídos no estudo, a média da idade foi 8 anos (2-38 anos). A PEDI apresentou desempenho funcional abaixo das expectativas nos domínios de autocuidado e mobilidade em 33,3% quando comparada com grupos de crianças brasileiras com desenvolvimento típico da mesma idade avaliada. A diminuição da função social foi encontrada em apenas um único caso. De acordo com a MIF, dos 12 pacientes avaliados (idade> 7,5 anos), 58,3% foram classificados como dependência modificada e 41,7% como independência modificada. A distância média no 6MWTfoi significativamente menor do que o previsto, 263 m em G1 (crianças, n = 7) e 336 m em G2 (adolescentes e adultos, n = 6), p<0,001. A FMR também foi menor do que o previsto em ambos os grupos, com exceção em G1. Conclusões: a capacidade funcional e a FMR foram signif icativamente reduzidas em indivíduos com MPS VI, com diminuição da independência funcional em um terço dos pacientes. Portanto, o seguimento multidisciplinar no acompanhamento dessa população é essencial para prevenir, diagnosticar e tratar complicações precocemente.

Targeting Chondroitin Sulfate Glycosaminoglycans to Treat Cardiac Fibrosis in Pathological Remodeling.

BACKGROUND: Heart failure is a leading cause of mortality and morbidity, and the search for novel therapeutic approaches continues. In the monogenic disease mucopolysaccharidosis VI, loss-of-function mutations in arylsulfatase B lead to myocardial accumulation of chondroitin sulfate (CS) glycosaminoglycans, manifesting as myriad cardiac symptoms. Here, we studied changes in myocardial CS in nonmucopolysaccharidosis failing hearts and assessed its generic role in pathological cardiac remodeling. METHODS: Healthy and diseased human and rat left ventricles were subjected to histological and immunostaining methods to analyze glycosaminoglycan distribution. Glycosaminoglycans were extracted and analyzed for quantitative and compositional changes with Alcian blue assay and liquid chromatography-mass spectrometry. Expression changes in 20 CS-related genes were studied in 3 primary human cardiac cell types and THP-1-derived macrophages under each of 9 in vitro stimulatory conditions. In 2 rat models of pathological remodeling induced by transverse aortic constriction or isoprenaline infusion, recombinant human arylsulfatase B (rhASB), clinically used as enzyme replacement therapy in mucopolysaccharidosis VI, was administered intravenously for 7 or 5 weeks, respectively. Cardiac function, myocardial fibrosis, and inflammation were assessed by echocardiography and histology. CS-interacting molecules were assessed with surface plasmon resonance, and a mechanism of action was verified in vitro. RESULTS: Failing human hearts displayed significant perivascular and interstitial CS accumulation, particularly in regions of intense fibrosis. Relative composition of CS disaccharides remained unchanged. Transforming growth factor-ß induced CS upregulation in cardiac fibroblasts. CS accumulation was also observed in both the pressure-overload and the isoprenaline models of pathological remodeling in rats. Early treatment with rhASB in the transverse aortic constriction model and delayed treatment in the isoprenaline model proved rhASB to be effective at preventing cardiac deterioration and augmenting functional recovery. Functional improvement was accompanied by reduced myocardial inflammation and overall fibrosis. Tumor necrosis factor-α was identified as a direct binding partner of CS glycosaminoglycan chains, and rhASB reduced tumor necrosis factor-α-induced inflammatory gene activation in vitro in endothelial cells and macrophages. CONCLUSIONS: CS glycosaminoglycans accumulate during cardiac pathological remodeling and mediate myocardial inflammation and fibrosis. rhASB targets CS effectively as a novel therapeutic approach for the treatment of heart failure.

Long-Term Galsulfase Treatment Associated With Improved Survival of Patients With Mucopolysaccharidosis VI (Maroteaux-Lamy Syndrome): 15-Year Follow-Up From the Survey Study

Abstract Mucopolysaccharidosis VI (MPS VI) is a progressive lysosomal storage disorder with multiorgan and multisystemic pathology. Currently, galsulfase enzyme replacement therapy (ERT) is the only approved treatment for MPS VI. A crosssectional survey study of 121 patients with MPS VI conducted in 2001 to 2002 and a 10-year follow-up study of the same patients (resurvey study; ClinicalTrials.gov NCT01387854) found that those receiving galsulfase at any time showed physical improvements and a lower mortality rate (16.5%) versus treatment-naive patients (50%). After *15 years, galsulfasetreated patients (n » 104) continue to have a survival advantage over treatment-naive patients (n » 14), as demonstrated by a 24% versus 57% mortality rate. This survival advantage is further supported by data from the commercial use of galsulfase (2005-2016), which show a 5-year mortality rate for galsulfase-treated patients of 12.5%. Together, these findings suggest that galsulfase ERT can increase life expectancies for patients with MPS VI over a period of at least 15 years.

Another Novel Missense Mutation in ARSB Gene in Iran.

Mucopolysaccharidosis VI (MPS-VI) is an infrequent autosomal recessive disorder caused by mutations in ARSB gene and deficiency in lysosomal enzyyme ARSB activities subsequently. This enzyme is essential for the breaking of glycosaminoglycans (GAGs) such as dermatan sulfate and chondroitin sulfate. ARSB dysfunction results in imperfect breakdown of GAGs and their accumulation in urine. Mutations in ARSB gene are the main players in MPS-VI disease and its clinical consequences. Most reported mutations are point mutations but there are some other examples in literature. Here we report a novel missense mutation in ARSB gene that is inherited as an autosomal recessive mode and probably explain the clinical status of the proband. This mutation replaces the threonine 92 by proline and alters ARSB structure. This is the most feasible scenario for clinical condition we described here. This novel mutation should be remarked for PND and PGD to improve the health and management of such families.