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The present study aimed to compare the prevalence of oral problems between individuals with rare genetic diseases that affect skeletal development and individuals without rare diseases. A cross-sectional study was conducted with 210 individuals between two and fifty-four years of age: 105 with rare genetic diseases (27 with mucopolysaccharidosis [MPS] and 78 with osteogenesis imperfecta [OI]) and 105 without rare diseases. The rare genetic disease group was recruited from hospital units that provide care for patients with MPS and OI in five states of Brazil, and the other group was recruited from the same location. The participants were examined with regards to malocclusion, dental anomalies, dental caries, and gingivitis. A questionnaire was administered addressing individual, sociodemographic, and behavioral characteristics as well as dental history. A descriptive analysis was performed, followed by unadjusted and adjusted binary logistic regression analyses. The mean age was 14.1 ± 12.2 years. Individuals with a rare disease were 12.9-fold more likely to have some type of oral problem (95% CI: 3.7-44.7) compared to the group without rare diseases. The prevalence of oral problems was higher among Brazilians with MPS and OI compared to normotypical individuals.

Background: This cross-sectional study aimed to describe and discuss the epidemiology of mucopolysaccharidoses (MPS) in Tunisia., Methods: Patients diagnosed with a MPS disorder in two referral laboratories in Tunisia between 1999 and 2021 were included. Diagnosis was based on clinical and radiological features and analysis of urinary glycosaminoglycans, and enzyme assay in some of the patients., Results: Over the twenty-two years, 199 patients were diagnosed with MPS in Tunisia. The disorder was classified as MPS I, MPS II, MPS III, MPS IV, and MPS VI in 15.07%, 1.5%, 38.69%, 17.08% and 7.03% patients, respectively. Due to the lack of enzyme analysis, the disorder was classified as MPS I or II in 20.6% of patients, and no cases of MPS VII and IX were documented. Gender-ratio was 1.5 and age at diagnosis varied from 3 months to 18 years with a median of 46 months. Patients originated from across Tunisia, and no hotspot site was identified. During the survey period, 3,822,983 births occurred, which provides an estimated global incidence of MPS of 1:20,123 live births (4.97 per 100,000). MPS III was the most frequent type with an estimated incidence of 1.91 cases per 100,000 newborns., Conclusions: MPS disorders, especially MPS III are relatively frequent in Tunisia, likely due to a high rate of consanguineous marriages. Implementation of enzyme and genetic tests in Tunisia will allow diagnosis confirmation and subtype recognition, as well as accurate genetic counseling and prenatal diagnosis for MPS.

The mucopolysaccharidoses (MPS) are a group of rare genetic disorders characterized by progressive multisystem disease. We sought to identify the perceptions and support needs of siblings, who often have lifelong relationships and assume important roles for their brothers and sisters with MPS. We designed an online survey to ask siblings about their experiences through a series of Likert statements and open-ended questions. A mixed methods approach was used to analyze the results. We analyzed eligible responses from 97 participants, ages 18.1-61.2 years, who have brothers and sisters with MPS I, II, III, IV, and VI. Participants reported serving as caregivers for their siblings with MPS, at all ages. While over 62% of siblings often felt sad because they have a brother or sister with MPS, over 90% of siblings reported that they like their brothers and sisters and expressed feelings of pride. Siblings wanted information about MPS, guidance for caregiving activities, genetic counseling, and opportunities to connect with other siblings. Families and professionals should acknowledge the unique experiences and needs of siblings, include siblings in medical conversations and care plans when appropriate, and connect siblings to resources for informational and emotional support., (© 2021 Wiley Periodicals LLC.)

Mucopolysaccharidoses, a rare inherited disorder of lysosomal storage, account for less than 0.1% of all genetic diseases.  The penetrance is highly variable and clinically it varies from severe fetal-neonatal forms to attenuated diseases diagnosed in adult individuals. The majority of the patients have been reported to show cardiac abnormalities since pediatric age, however, there is a minority of patients with attenuated disease diagnosed in the adolescent and adult age. The haematopoietic stem cell transplantation and enzyme replacement therapy are the current therapies for these disorders. Thanks to these treatments, Mucopolysaccharidoses patients live longer than in the past. Even though enzyme replacement therapy has been demonstrated to reduce left ventricular mass in patients with cardiomyopathy, the efficacy on valve abnormalities has not been clearly demonstrate yet. Furthermore, thanks to the current therapy, to better understanding and to the advent on new technologies, an increasing number of adolescent and adult patients diagnosed with MPS are followed up in the adult echocardiographic laboratory. Indeed, a systematic descriptive study describing the echocardiographic features of valvular involvement and their evolution in adolescent and adult patients lacks of medical literature and this was the aim of our investigation. Our results showed that all the valves are affected, mainly the mitral valve with a higher prevalence compared to the pediatric age.  The echocardiographic features of MPS differs from other valvular disease of adolescent and adult age, and knowing them can avoid misdiagnosis. Our observations also suggest that the progression of cardiac involvement slows after the initiation of the therapy in our group of age. Further studies on larger population are required to confirm our results.

Background: Mucopolysaccharidoses (MPS) are rare, inherited lysosomal storage disorders characterized by progressive multiorgan involvement. Previous studies on incidence and prevalence of MPS mainly focused on countries other than the United States (US), showing considerable variation by country. This study aimed to identify MPS incidence and prevalence in the US at a national and state level to guide clinicians and policy makers., Methods: This retrospective study examined all diagnosed cases of MPS from 1995 to 2015 in the US using the National MPS Society database records. Data included year of birth, patient geographic location, and MPS variant type. US population information was obtained from the National Center for Health Statistics. The incidence and prevalence rates were calculated for each disease. Incidence rates were calculated for each state., Results: We obtained information from 789 MPS patients during a 20-year period. Incidence of MPS in the US was found to be 0.98 per 100,000 live births. Prevalence was found to be 2.67 per 1 million. MPS I, II, and III had the highest incidence rate at birth (0.26/100,000) and prevalence rates of 0.70-0.71 per million. Birth incidences of MPS IV, VI, and VII were 0.14, 0.04 and 0.027 per 100,000 live births., Conclusions: This is the most comprehensive review of MPS incidence and prevalence rates in the US. Due to the large US population and state fragmentation, US incidence and prevalence were found to be lower than other countries. Nonetheless, state-level studies in the US supported these figures. Efforts should be focused in the establishment of a national rare disease registry with mandated reporting from every state as well as newborn screening of MPS.

Background: In this study, the prevalence of different types of mucopolysaccharidoses (MPS) was estimated based on data from the exome aggregation consortium (ExAC) and the genome aggregation database (gnomAD). The population-based allele frequencies were used to identify potential disease-causing variants on each gene related to MPS I to IX (except MPS II)., Methods: We evaluated the canonical transcripts and excluded homozygous, intronic, 3', and 5' UTR variants. Frameshift and in-frame insertions and deletions were evaluated using the SIFT Indel tool. Splice variants were evaluated using SpliceAI and Human Splice Finder 3.0 (HSF). Loss-of-function single nucleotide variants in coding regions were classified as potentially pathogenic, while synonymous variants outside the exon-intron boundaries were deemed non-pathogenic. Missense variants were evaluated by five in silico prediction tools, and only those predicted to be damaging by at least three different algorithms were considered disease-causing., Results: The combined frequencies of selected variants (ranged from 127 in GNS to 259 in IDUA) were used to calculate prevalence based on Hardy-Weinberg's equilibrium. The maximum estimated prevalence ranged from 0.46 per 100,000 for MPSIIID to 7.1 per 100,000 for MPS I. Overall, the estimated prevalence of all types of MPS was higher than what has been published in the literature. This difference may be due to misdiagnoses and/or underdiagnoses, especially of the attenuated forms of MPS. However, overestimation of the number of disease-causing variants by in silico predictors cannot be ruled out. Even so, the disease prevalences are similar to those reported in diagnosis-based prevalence studies., Conclusion: We report on an approach to estimate the prevalence of different types of MPS based on publicly available population-based genomic data, which may help health systems to be better prepared to deal with these conditions and provide support to initiatives on diagnosis and management of MPS.

Background: Mucopolysaccharidoses (MPSs) are a group of inherited metabolic diseases, which are characterized by the accumulation of glycosaminoglycans, and eventually lead to the progressive damage of various tissues and organs., Methods: An epidemiological study of MPS in Taiwan was performed using multiple sources. The survival and diagnostic age for different types of MPS between 1985 and 2019 were evaluated., Results: Between 1985 and 2019, there were 175 patients diagnosed with MPS disorders in the Taiwanese population, with a median diagnostic age of 3.9 years. There were 21 (12%), 78 (45%), 33 (19%), 32 (18%) and 11 (6%) patients diagnosed with MPS I, II, III, IV and VI, respectively, with median diagnostic ages of 1.5, 3.8, 4.7, 4.5 and 3.7 years, respectively. Diagnosis of MPS patients was significantly earlier in recent decades (p < 0.01). Pilot newborn screening programs for MPS I, II, VI, IVA, and IIIB were progressively introduced in Taiwan from 2016, and 48% (16/33) of MPS patients diagnosed between 2016 and 2019 were diagnosed by one of these screening programs, with a median diagnostic age at 0.2 years. For patients born between 2016 and 2019, up to 94% (16/17) were diagnosed with MPS via the newborn screening programs. At the time of this study, 81 patients had passed away with a median age at death of 15.6 years. Age at diagnosis was positively correlated with life expectancy (p < 0.01). Life expectancy also significantly increased between 1985 and 2019, however this increase was gradual (p < 0.01)., Conclusions: The life expectancy of Taiwanese patients with MPS has improved in recent decades and patients are being diagnosed earlier. Because of the progressive nature of the disease, early diagnosis by newborn screening programs and timely implementation of early therapeutic interventions may lead to better clinical outcomes.

Mucopolysaccharidoses (MPS) are a subtype of lysosomal storage disorders (LSDs) characterized by the deficiency of the enzyme involved in the breakdown of glycosaminoglycans (GAGs). Mucopolysaccharidosis type I (MPS I, Hurler Syndrome) was endorsed by the U.S. Secretary of the Department of Health and Human Services for universal newborn screening (NBS) in February 2016. Its endorsement exemplifies the need to enhance the accuracy of diagnostic testing for disorders that are considered for NBS. The progression of MPS disorders typically incudes irreversible CNS involvement, severe bone dysplasia, and cardiac and respiratory issues. Patients with MPS have a significantly decreased quality of life if untreated and require timely diagnosis and management for optimal outcomes. NBS provides the opportunity to diagnose and initiate treatment plans for MPS patients as early as possible. Most newborns with MPS are asymptomatic at birth; therefore, it is crucial to have biomarkers that can be identified in the newborn. At present, there are tiered methods and different instrumentation available for this purpose. The screening of quick, cost-effective, sensitive, and specific biomarkers in patients with MPS at birth is important. Rapid newborn diagnosis enables treatments to maximize therapeutic efficacy and to introduce immune tolerance during the neonatal period. Currently, newborn screening for MPS I and II has been implemented and/or in pilot testing in several countries. In this review article, historical aspects of NBS for MPS and the prospect of newborn screening for MPS are described, including the potential tiers of screening.

Mucopolysaccharidosis are lysosomal storage diseases, secondary to the accumulation of mucopolysaccharides. Type 1 mucopolysaccharidosis is the most common form and affects between 0.69 and 1.66 newborns per 100,000. The severity of mucopolysaccharidosis is variable with lethal forms in utero and attenuated forms diagnosed in adults. The most common symptoms are short stature, facial dysmorphism, chronic articular pains that can mimic chronic inflammatory rheumatism, axial and peripheral bone involvement, hepatosplenomegaly and an early carpal tunnel. Depending on the type of mucopolysaccharidosis, corneal, cerebral or cardiac involvements are possible. Screening is based on the analysis of urinary glycosaminoglycans. The deficient enzyme assay and the gene analysis confirm the diagnosis. Mucopolysaccharidosis recognition is important for patient management and family screening. In addition, specific enzyme replacement therapy exists for certain types of mucopolysaccharidosis. Role of clinician is important to evoke and diagnose mucopolysaccharidosis., (Copyright © 2019 Société Nationale Française de Médecine Interne (SNFMI). Published by Elsevier Masson SAS. All rights reserved.)

Several studies have been published on the frequency of the mucopolysaccharidoses (MPS) in different countries. The objective of the present study was to estimate the birth prevalence (BP) of MPS in Brazil. MPS diagnosis registered at MPS-Brazil Network and in Instituto Vidas Raras were reviewed. BP was estimated by (a) the number of registered patients born between 1994 and 2015 was divided by the number of live births (LBs), and (b) a sample of 1,000 healthy individuals was tested for the most frequent variant in IDUA gene in MPS I (p.Trp402Ter) to estimate the frequency of heterozygosity and homozygosity. (a) The BP based on total number of LBs was (cases per 100,000 LBs): MPS overall: 1.25; MPS I: 0.24; MPS II: 0.37; MPS III: 0.21; MPS IV: 0.14; MPS VI: 0.28; MPS VII: 0.02. (b) The overall frequency of p.Trp402Ter was 0.002. Considering the frequency of heterozygotes for the p.Trp402Ter IDUA variant in the RS state, the frequency of this variant among MPS I patients and the relative frequency of the different MPSs, we estimated the birth prevalence of MPS in total and of each MPS type, as follows: MPS overall: 4.62; MPS I: 0.95; MPS II: 1.32; MPS III: 0.56; MPS IV: 0.57; MPS VI: 1.02; MPS VII: 0.05. This study provided original data about BP and relative frequency of the MPS types, in Brazil, based on the frequency of the commonest IDUA pathogenic variant and in the records of two large patient databases., (© 2020 Wiley Periodicals, Inc.)

Previously, we reported a novel disease of impaired glycosaminoglycans (GAGs) metabolism without deficiency of known lysosomal enzymes-mucopolysaccharidosis-plus syndrome (MPSPS). MPSPS, whose pathophysiology is not elucidated, is an autosomal recessive multisystem disorder caused by a specific mutation p.R498W in the VPS33A gene. VPS33A functions in endocytic and autophagic pathways, but p.R498W mutation did not affect both of these pathways in the patient's skin fibroblast. Nineteen patients with MPSPS have been identified: seventeen patients were found among the Yakut population (Russia) and two patients from Turkey. Clinical features of MPSPS patients are similar to conventional mucopolysaccharidoses (MPS). In addition to typical symptoms for conventional MPS, MPSPS patients developed other features such as congenital heart defects, renal and hematopoietic disorders. Diagnosis generally requires evidence of clinical picture similar to MPS and molecular genetic testing. Disease is very severe, prognosis is unfavorable and most of patients died at age of 10-20 months. Currently there is no specific therapy for this disease and clinical management is limited to supportive and symptomatic treatment.

Background: Mucopolysaccharidoses (MPSs) are a group of rare lysosomal storage disorders characterized by the accumulation of glycosaminoglycans in various tissues and organs. Ocular problems that affect the cornea, trabecular meshwork, sclera, retina, and optic nerve are very common in these patients. However, there was limited literature focusing on comprehensive ocular findings in different types of MPS., Methods: We retrospectively reviewed the clinical ophthalmologic features and electrodiagnostic results of 50 Taiwanese patients with a diagnosis of MPS (34 males and 16 females; age range, 1.1-34.9 years; nine with MPS I, 17 with MPS II, 17 with MPS IV, and seven with MPS VI)., Results: Among 44 patients with available data for visual acuity, 15 patients (34%) had a visual acuity of less than 0.5 (6/12) equivalent in their better eye, including 71% of those with MPS VI, 38% with MPS IV, 29% with MPS I, and 14% with MPS II. Severe corneal opacities existed in 57% of MPS VI patients and 11% of MPS I patients, compared with none for MPS II and MPS IV patients. Among 80 eyes with available data of refraction, 11 eyes (14%) had myopia (≦-0.50 D), 55 eyes (69%) had hyperopia (≧0.50 D), and 55 eyes (69%) had high astigmatism (≧1.50 D). Ocular hypertension was found in 45% (28/62) of eyes. There were 16% (14/90), 11% (10/90), 13% (12/90), 31% (27/86), and 79% (30/38) of MPS eyes with lens opacities, optic disc swelling, optic disc cupped, retinopathy, and visual pathway dysfunction, respectively. Intraocular pressure was positively correlated with the severity of corneal opacity (p < 0.01)., Conclusions: Ocular complications with significant reduction in visual acuity are common in MPS patients. Diagnostic problems may arise in these patients with severe corneal opacification, especially for those with MPS VI and MPS I., (© 2019 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.)

Mucopolysaccharidoses are a group of rare lysosomal storage diseases including a great number of polymorph syndromes, each being related to a particular mutation responsible for a deficiency of glycosaminoglycan degrading enzymes, leading to an accumulation of glycosaminoglycans in tissues. Many of them are diagnosed in children or teenagers and have a severe prognosis because of organ failure, and are consequently usually not seen by the adult rheumatologist. However, some of them have a more progressive presentation, with musculoskeletal symptoms at the forefront and a lifespan that nearly reaches that of the general population. These milder forms are more likely to be diagnosed in adults, in patients who have suffered for years and sometimes even decades with unrecognized mucopolysaccharidosis. Indeed, they can sometimes mimic inflammatory rheumatic disorders, and therefore be misdiagnosed for a long time. Recognition and diagnosis of these attenuated forms can be a real challenge as they lead to moderate and/or nonspecific symptoms such as joint pain or stiffness. Hence, rheumatologists should know about them. Early diagnostic is essential since specific treatment, like enzyme replacement therapy, is now available for some subtypes and might, if given early, slow down the development of tissue damage, which is unfortunately irreversible. This article provides the opportunity to review the main clinical and radiographic features, the diagnostic strategy and the update of management, which should be multidisciplinary and led by an experienced physician in a reference centre. The contribution of the rheumatologist is important to ensure symptom control and prevent complications., (Copyright © 2017 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.)

The aim of this study was to obtain data about the epidemiology of the different types of mucopolysaccharidoses in Japan and Switzerland and to compare with similar data from other countries. Data for Japan was collected between 1982 and 2009, and 467 cases with MPS were identified. The combined birth prevalence was 1.53 per 100,000 live births. The highest birth prevalence was 0.84 for MPS II, accounting for 55% of all MPS. MPS I, III, and IV accounted for 15, 16, and 10%, respectively. MPS VI and VII were more rare and accounted for 1.7 and 1.3%, respectively. A retrospective epidemiological data collection was performed in Switzerland between 1975 and 2008 (34years), and 41 living MPS patients were identified. The combined birth prevalence was 1.56 per 100,000 live births. The highest birth prevalence was 0.46 for MPS II, accounting for 29% of all MPS. MPS I, III, and IV accounted for 12, 24, and 24%, respectively. As seen in the Japanese population, MPS VI and VII were more rare and accounted for 7.3 and 2.4%, respectively. The high birth prevalence of MPS II in Japan was comparable to that seen in other East Asian countries where this MPS accounted for approximately 50% of all forms of MPS. Birth prevalence was also similar in some European countries (Germany, Northern Ireland, Portugal and the Netherlands) although the prevalence of other forms of MPS is also reported to be higher in these countries. Birth prevalence of MPS II in Switzerland and other European countries is comparatively lower. The birth prevalence of MPS III and IV in Switzerland is higher than in Japan but comparable to that in most other European countries. Moreover, the birth prevalence of MPS VI and VII was very low in both, Switzerland and Japan. Overall, the frequency of MPS varies for each population due to differences in ethnic backgrounds and/or founder effects that affect the birth prevalence of each type of MPS, as seen for other rare genetic diseases. Methods for identification of MPS patients are not uniform across all countries, and consequently, if patients are not identified, recorded prevalence rates will be aberrantly low., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objective: To determine the relative frequency and clinical features of different varieties of mucopolysaccharidosis., Study Design: Descriptive study., Place and Duration of Study: Department of Pediatric Gastroenterology, Hepatology and Nutrition, The Children's Hospital and The Institute of Child Health, Lahore, from January 2013 to December 2015., Methodology: All patients who had any feature suggestive of mucopolysaccharidosis were screened with detailed history, clinical examination and skeletal survey. Urine samples for glycosaminoglycan (GAGs) levels and dried blood samples for enzyme analysis were sent. Patients who were confirmed to be suffering from mucopolysaccharidosis were included in the study. The data was analysed using SSPS version 20., Results: A total of 90 confirmed MPS cases, 52 males and 38 females, median age 42 months, were included. Hurler/Hurler-Scheie syndrome was the most frequent (75, 83.33%) followed by Morquio (6, 6.67%), Sanfilippo (5, 5.56%), Maroteaux-Lamy (3, 3.33%) and Hunter (1, 1.11%) syndromes. Consanguinity was present in 79 (87.78%) cases. Common features were hepatomegaly (80, 88.89%), coarse facies (70, 77.78%), splenomegaly (67, 74.44%), and bone disease (48, 53.33%)., Conclusion: Most common variety of mucopolysaccharidosis was Hurler/Hurler Scheie followed by Morquio syndrome. Most of the patients were born to consanguineous parents. Common clinical features were coarse facies, hepatosplenomegaly and dysostosis multiplex.

Background: Most inborn errors of metabolism result in mental retardation and death due to accumulation of abnormal metabolites in the tissues. The presence of abnormal metabolites in the urine of mentally retarded individuals has been used worldwide for detection of inborn errors of metabolism. The purpose of the study is to determine the prevalence of inborn error of metabolism in mentally retarded children., Methods: Random urine samples were collected from mentally retarded children at two institutes in Kathmandu, and also from 60 normal children from Duwakot, Nepal after obtaining consent from their parents. Urine was then tested for the presence of amino acids, keto-acids, mucopolysaccharides, fructose, glucose and protein using simple qualitative color reactions in the laboratory., Results: The tests detected eight cases of Phenylketonuria, which turned out to be false positive on paper chromatography. Three cases of presence of ketone bodies (acetoacetate), ten cases of α-ketoaciduria, two cases of mucopolysaccharidosis and twelve cases of fructosuria amongst the sixty-two urine samples were also found., Conclusions: Certain aminoacidurias, ketoacidurias and mucopolysaccharidoses might be present in the Nepalese population. Within consideration of errors, the samples tested positive should be evaluated by a higher end method to confirm the utility of these simple and cheap chemical tests.

Comprehensive analytical and diagnostic performance of urinary quantitative GAG analysis with dimethylmethylene blue (DMB) and the age-specific reference ranges were determined in Turkish population, which has a high incidence of MPSs. Precision, linearity, recovery and accuracy/trueness, limits, stability, and effect of interferents were tested according to CLSI guideline. Clinical performance was evaluated with ROC analyses including 45 MPS patients. Intra-day and inter-day precisions were <5% and <11% (CV), respectively. LoD was 9.12mg/L and LoQ was 23.3mg/L. The highest reference values for urinary GAG excretion were determined in an age-specific manner. In the 2-13years age cohort, a cut-off of 89.86mg/g creatinine resulted in 98.07% sensitivity and 93.33% specificity. Proteinuria and hematuria interfered with analysis in some instances. Neither leukocyturia nor pH changes affected the assay. Stability analysis indicated that freezing urine samples for transfer is unnecessary. Of the 45 MPS patient samples evaluated, only three tested negative including MPS II, IVA and VI. Despite limitations due to low levels of urinary GAG excretion in some cases, urinary GAG analysis with DMB with its technical simplicity, low cost, and precise quantitative results, is a valuable screening method, particularly in populations with a high rate of MPSs., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: The objective of the study was to compare mean values for birth body length and weight between patients with mucopolysaccharidosis (MPS) and the general population., Methods: A retrospective analysis of birth anthropometric data was performed for patients (n = 103) with MPS I, II, and VI. Two-tailed t tests were used to compare mean values for body length and weight at birth between patients with MPS and the general population., Results: Mean values for birth body length and weight for all studied groups were greater than in the general population. For body length the differences were statistically significant. When considered individually, 53% of patients were large for gestational age (LGA) and 30% were macrosomic. The highest percentage of LGA was observed in MPS II males and MPS VI females (55% and 56%, respectively), while the highest percentage of macrosomia was observed in MPS VI males (36%)., Conclusion: At the time of birth, MPS patients were larger than those in the general population. High birth weight and/or LGA can be suggestive of MPS disease and should raise suspicion aiding early disease recognition., (Copyright © 2015. Published by Elsevier B.V.)

The aim of this study was to determine the prevalence rates of mucopolysaccharidoses in Poland and to compare them with other European countries. A retrospective epidemiological survey covering the period between 1970 and 2010 was implemented. Multiple ascertainment sources were used to identify affected patients. The overall prevalence of mucopolysaccharidoses in the Polish population was 1.81 per 100,000. Five different mucopolysaccharidoses were diagnosed in a total of 392 individuals. MPS III was the most frequent mucopolysaccharidosis, with a birth prevalence of 0.86 per 100,000 live births. A prevalence of approximately 0.22 cases per 100,000 births was obtained for MPS I. For MPS II, the prevalence was estimated as 0.45 cases per 100,000 births; for MPS IV A and B as 0.14 cases in 100,000 births; and that for MPS VI as 0.03 cases per 100,000 births. 1. The prevalence pattern of mucopolysaccharidosis in Poland is lower when compared to the prevalence reported for other European countries, such as the Netherlands, Czech Republic, or Germany, but similar to countries like Sweden and Denmark. 2. Different frequencies of the various forms of mucopolysaccharidosis were observed. 3. In the case of MPS VI, the incidence values for Poland were the lowest of all the studies previously published so far.

Purpose: The mucopolysaccharidoses (MPS) are a group of rare lysosomal storage disorders, characterized by the accumulation of glycosaminoglycans within multiple organ systems including the eye. This study aimed to determine the prevalence of glaucoma in patients with MPS, as well as the characteristics, diagnosis and management of patients with MPS and glaucoma., Methods: A multicentre retrospective case-note review was carried out by ophthalmologists from four tertiary referral centres to identify patients with MPS who had been treated for glaucoma. Clinical ophthalmological data were collected using standardized data collection forms., Results: Fourteen patients were identified (27 eyes) of 294 patients with MPS. The prevalence of glaucoma ranged from 2.1% to 12.5%. The median age at diagnosis of glaucoma was 8 years. Diagnostic evaluation of glaucoma was incomplete in many patients: intraocular pressure was documented in all eyes, but optic disc appearance was only assessed in 67%, central corneal thickness in 26%, visual fields in 19% and iridocorneal angle in 15%., Conclusions: Patients with MPS need regular assessment for possible glaucoma including during childhood. Multiple factors contribute to the challenges of assessment, diagnosis and monitoring of glaucoma in these patients., (© 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Background: While clinical observations suggest that many patients with mucopolysaccharidosis (MPS) experience chronic pain, few studies have assessed its extent and impact. We therefore investigated its prevalence in patients with all types of MPS in the Netherlands. We also examined the association between pain and health related quality of life (HRQoL) and other clinical variables., Methods: We conducted a nationwide MPS survey that used questionnaires on MPS and disease-related symptoms (MPS-specific questionnaire), developmental level (Vineland Screener 0-6 years), quality of life (PedsQl and SF-36), and disability (Childhood Health Assessment Questionnaire). Depending on their age and developmental level, patients or their parents were asked to assess pain by keeping a pain diary for five consecutive days: either the Non-communicating Children's Pain Checklist - Revised (3-18 years intellectually disabled and children <8 years), the VAS-score (> 18 years), or the Faces Pain Scale - Revised (8-18 years)., Results: Eighty-nine MPS patients were invited, 55 of whom agreed to participate (response rate 62 %; median age 10.9 years, range 2.9-47.2 years). They covered a wide spectrum in all age groups, ranging from no pain to severe pain. Forty percent scored above the cut-off value for pain. Most reported pain sites were the back and hips. While the MPS III group experienced the highest frequency of pain (52.9 %), 50 % of patients with an intellectual disability seemed to experience pain, versus 30 % of patients with a normal intelligence. MPS patients scored much lower (i.e., more pain) than a random sample of the Dutch population on the bodily pain domain of the SF-36 scale and the PedsQl., Conclusion: With or without intellectual disabilities, many MPS patients experience pain. We recommend that standardized pain assessments are included in the regular follow-up program of patients with MPS.

Background: Mucopolysaccharidoses (MPS) are hereditary storage diseases; airway management typically worsens in these patients with the progression of the disease., Objective(s): To assess the incidence of perioperative complications in children with MPS and the impact of enzyme replacement therapy (ERT) followed by hematopoietic stem cell transplantation (HSCT)., Methods: The records of patients with MPS treated with ERT followed by HSCT, who received anesthesia at the Wilhelmina Children's Hospital between 2003 and 2012, were reviewed. Data were collected on incidence of perioperative respiratory and cardiovascular complications and the impact of treatment and age., Results: Nineteen children with MPS were identified (including 17 Hurler patients), who received ERT treatment followed by HSCT. Median age at start of treatment was 14 (range: 7-43) months. Patients were anesthetized 136 times. The incidence of respiratory and cardiovascular complications was 24% and 4%, respectively. Airway management by face mask was difficult in 7%. There were no problems with the laryngeal mask airway. Tracheal intubation was difficult in 25% and failed in 10%; using a video laryngoscope was most successful (89%), followed by classic laryngoscope (67%) and fiber-optic scope (20%). Multivariate logistic regression analyses showed that the incidence of perioperative respiratory problems did not increase with age or decrease after start of treatment., Conclusion: Perioperative airway management was most successful using a laryngeal mask airway or video laryngoscope. Treatment with ERT followed by HSCT and patient age did not influence the incidence of perioperative respiratory problems., (© 2014 John Wiley & Sons Ltd.)

Introduction: Mucopolysaccharidoses are a group of infrequent disorders caused by the lysosomal deposit of glycosaminoglycans. Its incidence is quite variable among the countries where it has been documented. In Brazil, disorder frequencies have been reported, but in Colombia information on them is scarce., Objectives: The frequency and spatial aggregations of the mucopolysaccharidoses were estimated by a retrospective study in two central Colombian provinces., Materials and Methods: The records of patients and live newborns between 1998-2007 were reviewed from several reference institutions for genetic diseases. From these records, the frequencies for each mucopolysaccharidosis were estimated. The spatial aggregation of the cases was analyzed using the SaTScan software., Results: The combined frequency for all the mucopolysaccharidoses was 1.98 cases per 100,000 live newborns. MPS IV had the highest frequency with 0.68 cases per 100,000 live newborns and MPS III showed a lower frequency of 0.17/100,000. Three spatial aggregation areas were indicated for MPS I, MPS III and MPS IV., Conclusion: The combined frequency for all the mucopolysaccharidoses has been reported, with type IV the most frequent and the type VII in second place. The data herein constitute a record subset and, in spite of the difficulties inherent to the data retrieval in Colombia, they are a valid estimate of the frequencies of these diseases in central Colombia.

Previous studies on the prevalence of mucopolysaccharidoses (MPS) in different populations have shown considerable variations. There are, however, few data with regard to the prevalence of MPSs in Fenno-Ugric populations or in north-eastern Europe, except for a report about Scandinavian countries. A retrospective epidemiological study of MPSs in Estonia was undertaken, and live-birth prevalence of MPS patients born between 1985 and 2006 was estimated. The live-birth prevalence for all MPS subtypes was found to be 4.05 per 100,000 live births, which is consistent with most other European studies. MPS II had the highest calculated incidence, with 2.16 per 100,000 live births (4.2 per 100,000 male live births), forming 53% of all diagnosed MPS cases, and was twice as high as in other studied European populations. The second most common subtype was MPS IIIA, with a live-birth prevalence of 1.62 in 100,000 live births. With 0.27 out of 100,000 live births, MPS VI had the third-highest live-birth prevalence. No cases of MPS I were diagnosed in Estonia, making the prevalence of MPS I in Estonia much lower than in other European populations. MPSs are the third most frequent inborn error of metabolism in Estonia after phenylketonuria and galactosemia.

The mucopolysaccharidoses (MPSs) are inherited lysosomal storage disorders caused by the absence of functional enzymes that contribute to the degradation of glycosaminoglycans (GAGs). The progressive systemic deposition of GAGs results in multi-organ system dysfunction that varies with the particular GAG deposited and the specific enzyme mutation(s) present. Cardiac involvement has been reported in all MPS syndromes and is a common and early feature, particularly for those with MPS I, II, and VI. Cardiac valve thickening, dysfunction (more severe for left-sided than for right-sided valves), and hypertrophy are commonly present; conduction abnormalities, coronary artery and other vascular involvement may also occur. Cardiac disease emerges silently and contributes significantly to early mortality.The clinical examination of individuals with MPS is often difficult due to physical and, sometimes, intellectual patient limitations. The absence of precordial murmurs does not exclude the presence of cardiac disease. Echocardiography and electrocardiography are key diagnostic techniques for evaluation of valves, ventricular dimensions and function, which are recommended on a regular basis. The optimal technique for evaluation of coronary artery involvement remains unsettled.Standard medical and surgical techniques can be modified for MPS patients, and systemic therapies such as hematopoietic stem cell transplantation and enzyme replacement therapy (ERT) may alter overall disease progression with regression of ventricular hypertrophy and maintenance of ventricular function. Cardiac valve disease is usually unresponsive or, at best, stabilized, although ERT within the first few months of life may prevent valve involvement, a fact that emphasizes the importance of early diagnosis and treatment in MPS.

Introduction: Mucopolysaccharidoses (MPS), which belong to the family of inborn errors of metabolism, are characterised by their severe clinical manifestations (skeletal, neurological and visceral) and a chronic, progressive course leading to death at early stages of life. AIM. To accomplish an enzymatic diagnosis and characterise MPS within the Cuban population., Subjects and Methods: A total of 664 patients with a clinical suspicion of some type of MPS were referred to the Institute of Neurology and Neurosurgery in Havana in order to determine a possible enzymatic deficiency and to classify the type of MPS involved in each case. Enzymatic determinations of alpha-L-iduronidasa, alpha-N-acetylglucosaminidase, beta-galactosidase, arylsulphatase B and beta-glucuronidase were performed in leukocyte homogenate for MPS I, IIIB, IVB, VI and VII, respectively, in patients, parents and controls. RESULTS. In all, 42 cases of MPS were diagnosed: MPS I (62%, n = 26), MPS VI (29%, n = 12), MPS IIIB (7%, n = 3) and MPS IVB (2%, n = 1). No patients with MPS VII were identified. The patients diagnosed with MPS were of both sexes and ages ranged between 4 months and 10 years. The specific activity of the enzymes that were studied was deficient in patients with respect to parents and controls. The percentage of activity was lower in patients compared to parents., Conclusions: These studies made it possible to evaluate the enzymatic deficiencies and to establish the diagnosis of MPS I, MPS IIIB, MPS IVB, MPS VI and MPS VII in the Cuban population.

Background: The mucopolysaccharidoses (MPS) are a devastating heterogenous group of lysosomal storage disorders., Aim: To evaluate the epidemiological profile of MPS in Tunisia., Methods: we conducted a retrospective epidemiological survey covering the period 1970-2005. Multiple sources were used to identify affected patients., Results: Ninety six confirmed MPS cases were collected from 132 suspected cases found in the surveyed data. Of the ninety six confirmed cases, 20% were from multiplex families. Consanguinity was found in 83% of the families. The crude rate for all types of mucopolysaccharidoses was 2.3 cases in 100,000 live births. The prevalence of MPS type I, III and IV, those most frequently occurring in the collected data, were estimated at 0.63, 0.7 and 0.45 per 100,000 live births, respectively. The cumulative incidence of MPS type VI (0.3 per 105 live births) was higher than reported in European countries; but, it is likely that..., Conclusion: The reported frequency of all types of MPS in Tunisia is underestimated.

Background: The mucopolysaccharidoses (MPSs), a group of genetic lysosomal storage disorders, are associated with significant morbidity. Secondarily to specific associated anatomical abnormalities, MPS is associated with sleep disordered breathing (SDB), specifically obstructive sleep apnoea (OSA) that may confer additional morbidity. Few studies have examined SDB in children with MPS using full polysomnography (PSG) and thus the exact prevalence and severity of SDB is unknown. Further, successful treatments for SDB in this population have not been explored., Objectives: This study evaluated both SDB and the efficacy of treatments offered to children with MPS using PSG data., Patients and Methods: A retrospective chart review was conducted on all children with MPS and a history of suspected OSA who were referred to the Hospital for Sick Children, Toronto. Both baseline and follow up treatment PSG data were analysed. PSG data recorded included obstructive apnoea-hypopnoea index (OAHI) and central apnoea index (CAI)., Results: Fourteen patients (10 male) underwent a baseline PSG. Three of 14 children on ERT were excluded from the main analyses. The median (range) baseline parameters of the population (n = 11) were recorded. The age was 5.2 years (0.8-17.8) and the body mass index (BMI) was 19.9 (13.7-22.2). The OAHI was 6.6 (0.0-54.8); the CAI was 0.6 (0.0-2.6). Seven of 11 (64%) had evidence for OSA and 3/7 children were classified as having severe OSA (OAHI > 10). Of these, 5/7 children underwent treatment for OSA with 3/5 children showing a significant reduction in their OAHI. Further, the 2 patients on ERT therapy with OSA were also both successfully treated., Conclusions: Children with MPS have a high prevalence of significant OSA and thus should be carefully screened for OSA using full polysomnography and treated accordingly.

Previous studies on the incidence of the various types of mucopolysaccharidoses (MPS) in different populations have shown considerable variation. However, information regarding the incidence of MPS in the Asian population is lacking. An epidemiological study of the MPS disorders in Taiwan using multiple ascertainment sources was undertaken, and incidences of different types of MPS during the period of 1984-2004 were estimated. We compared our data with previous reports in different populations. The combined birth incidence for all MPS cases was 2.04 per 100,000 live births. MPS II (Hunter syndrome) had the highest calculated birth incidence of 1.07 per 100,000 live births (2.05 per 100,000 male live births), comprising 52% of all MPS cases diagnosed. The birth incidences of MPS I (Hurler syndrome), III (Sanfilippo syndrome), IV (Morquio syndrome), and VI (Maroteaux-Lamy syndrome) were 0.11, 0.39, 0.33, and 0.14 per 100,000 live births, respectively, which accounted for 6%, 19%, 16%, and 7% of all MPS, respectively. No cases of MPS III D (Sanfilippo syndrome type D), MPS IV B (Morquio syndrome type B), MPS VII (Sly syndrome) or MPS IX were ascertained during the study period. Overall incidence of MPS in Taiwan was consistent with that reported in Western populations. However, in contrast to the higher incidence of MPS I in most Western populations, this study showed a higher incidence of MPS II in Taiwan. It remains to be investigated whether this discrepancy is attributed to the under-diagnosis of MPS I in Taiwan or to ethnic differences.

Objective: To review of the natural history of airway disease in children with muccopolysaccharidoses (MPSs), which represent a group of hereditary progressive disorders caused by excessive accumulation of glycosaminoglycans in various tissues., Design: Retrospective medical chart review., Setting: Tertiary referral academic medical center., Patients: Twenty-seven children with MPSs., Main Outcome Measures: A review of the medical charts of 27 children with MPSs between February 1, 1984, and February 1, 2004, was performed to examine the natural history of airway disease., Results: Clinically upper airway obstruction was noted in 19 patients (70%) and necessitated a tracheotomy in 3 patients (11%). Fourteen of the 27 patients underwent bone marrow transplantation, and successful engraftment resulted in a significant decrease in obstructive symptoms in 13 of the 14 patients., Conclusions: Patients affected by MPSs require the vigilant attention of the otolaryngologist, as sleep apnea and upper airway obstruction are common complications. Successful bone marrow engraftment may alter the natural history of airway disease and result in substantial improvement in symptomatic airway disease in children with MPSs.

Aim: The aim of this study was to estimate the incidence and prevalence of mucopolysaccharidoses (MPS disorders) in Scandinavia., Methods: The retrospective period used for the incidence study covered the period from 1975 to 2004 in Sweden and Denmark and from 1979 to 2004 in Norway. Prevalence was derived from the number of MPS patients alive as of December 31, 2007., Results: The incidence of all MPS disorders was 1.75 cases in Sweden, 3.08 cases in Norway and 1.77 cases in Denmark per 100 000 newborns. The incidence of MPS I was the most common in all three countries, with 0.67, 1.85 and 0.54 cases per 100 000 newborns, respectively; for MPS II, numbers were 0.27, 0.13 and 0.27, respectively. For patients with other MPS disorders the incidence varied widely. The prevalence for all MPS disorders was 4.24, 7.06 and 6.03 per 1 000 000 inhabitants in Sweden, Norway and Denmark, respectively., Conclusion: From three Scandinavian countries the incidence of MPS disorders is retrospectively evaluated for 25 years in Norway and 30 years in Sweden and Denmark. Incidence and prevalence studies of lysosomal disorders are prerequisites for cost benefit calculations in the face of newly developed and expensive therapies in the future.

We have conducted a study to assess the opinions of parents of individuals with mucopolysaccharidoses (MPS) and adults with MPS regarding newborn screening (NBS) for this condition, as testing is now technically possible. A questionnaire including a number of hypothetical clinical scenarios about NBS for MPS was distributed to members of MPS support groups from United States and Australia. Questionnaires were returned by 249 members of the US (40% response) and Australian (38% response) support groups. Eleven respondents were adults with MPS and the rest were parents of individuals with MPS. Eighty-six percent of respondents indicated that they would have wanted NBS for their own children. Ninety-seven percent supported the use of NBS for MPS in situations where early treatment that favorably impacts on disease outcome is available, 87% supported NBS when a severe form of MPS was diagnosed, but no treatment is available that improves the long-term outcome and 84% supported NBS for mild MPS where no disease-modifying treatment is available. The most common reason cited in support of NBS was that NBS could avoid a delay in diagnosis and the accompanying distress that delayed diagnosis created. This study has identified strong support for the introduction of NBS for MPS from this group. Psychosocial benefits of screening may outweigh potential harms.

Objectives: To determine the clinical effectiveness and cost-effectiveness of the administration of intravenous enzyme replacement therapy (ERT) to symptomatic patients for the prevention of long-term damage and symptoms in Fabry's disease and in mucopolysaccharidosis type 1 (MPS1)., Data Sources: Electronic databases from inception up to mid-2004. Contact with clinical experts., Review Methods: Relevant studies were identified and assessed using recommended quality criteria., Results: The results suggested beneficial effects of ERT for Fabry's disease on measures of pain, cardiovascular function and some end-points reflecting neurosensory function. Renal function appeared to be stabilised by ERT. At present there are no utility-related health-related quality of life data on which to assess the relative health gain of ERT in MPS1. In order to be able to demonstrate the full extent of health gain from treatment, it was necessary to review the natural history of untreated patients in each disease in order to try to estimate the health loss prevented. The published information for Fabry's disease tallied with descriptions of a multi-system, life-threatening disorder particularly involving kidney, heart and brain with individual patients exhibiting many manifestations. The fragmentary information reviewed in 16 studies relevant to the natural history of MPS1 did not generate a coherent picture of disease progression and could provide little added value to published narrative reviews. For Fabry's disease, the mean cost per patient (50 kg) treated is around pounds sterling 85,000 per annum in England and Wales. The cost per patient varies considerably by dose. No published evidence reporting an economic evaluation of ERT for Fabry's disease was identified by this review. A dynamic decision model was constructed based on a birth cohort of male patients who are followed up until death. Owing to lack of information reported in the literature, many assumptions had to be applied. The key assumptions were that ERT returns patients to full health and a normal life expectancy. As far as possible, all assumptions favoured rather than detracted from the value of ERT. ERT was assumed to restore patients to full health in the base case. The estimated incremental cost-effectiveness ratio (ICER) in the base case was pounds sterling 252,000 per QALY (agalsidase beta). Univariate sensitivity analysis around the key assumptions produced ICERs ranging from pounds sterling 602,000 to pounds sterling 241,000. The base case unit cost of ERT was taken as pounds sterling 65.1/mg based on the cost of agalsidase beta. The unit cost would have had to be reduced to pounds sterling 9 to obtain an ICER of pounds sterling 30,000 per QALY. For MPS1, the mean cost per child patient (20 kg) treated is approximately pounds sterling 95,000 and an adult (70 kg) around pounds sterling 335,000 per annum in England and Wales. The cost per patient varies considerably by dose. There is no published evidence reporting an economic evaluation of ERT for MPS1 and no study was identified that reported the quality of life of MPS1 patients within a utility format. Furthermore, no or minimal information of the severity and rate of change of clinical manifestations of disease or the impact of ERT on these factors was identified. Information on the effect of ERT on mortality is also lacking owing to the relatively short time that the treatment has been available. Given this lack of data, it was not possible to develop a cost-effectiveness model of ERT treatment for MPS1 as the model would consist almost completely of assumptions based on no published evidence, leading to an incremental cost per QALY result that would be meaningless., Conclusions: Although ERT for treating the 'average' patient with Fabry's disease exceeds the normal upper threshold for cost-effectiveness seen in NHS policy decisions by over sixfold, and the value for MPS1 is likely to be of a similar order of magnitude, clinicians and the manufacturers argue that, as the disease is classified as an orphan disease under European Union legislation, it has special status, and the NHS has no option but to provide ERT. More information is required before the generalisability of the findings can be determined. Although data from the UK have been used wherever possible, this was very thin indeed. Nonetheless, even large errors in assumptions made will not reduce the ICER to anywhere near the upper level of treatments usually considered cost-effective. In order to overcome limited evidence on the natural history of the disease and the clinical effectiveness of the intervention, the establishment of disease-specific data registries is suggested to facilitate the process of technology assessment and improving patient care. These registries should attempt to include all affected patients in the UK, and collect longitudinal patient level data on clinically relevant problems, interventions received and quality of life in a utility format.

From 1991 to 2002, we managed 72 patients with mucopolysaccharidoses. We retrospectively reviewed the records of 37 for whom detailed physical findings and cardiovascular evaluation were available. Twenty patients had serial electrocardiographic (ECG) examinations, and none had arrhythmias. All 20 patients had low R wave voltage in V6. One type VI patient had ischaemic changes secondary to severe cardiomyopathy at the terminal stage of her disease. Among the 37 patients in whom echocardiography was performed, cardiovascular abnormalities progressed with age, although most had mild clinical signs and symptoms. The most common changes were abnormalities of the mitral and aortic valves hypertrophy of the interventricular septum, especially in types I, II, and VI. During the follow-up period of up to 5 years, 3 type II patients and I type VI patient expired. In at least 3 of these patients, death was related to cardiopulmonary failure. As MPS patients are surviving longer, complete cardiac evaluation at regular intervals is mandatory and should be part of their routine assessment.

In order to estimate the cumulative incidence rates of the mucopolysaccharidoses (MPS) in Germany, a retrospective epidemiological survey covering the period between 1980 and 1995 was implemented. Multiple ascertainment sources were used to identify affected patients. A prevalence of approximately 0.69 cases per 100,000 births was obtained for MPS I (Hurler phenotype). Within the study period, 4 patients with Hurler/Scheie phenotype and 7 cases with Scheie disease were detected. The cumulative incidence for MPS II (Hunter syndrome) was estimated as 0.64 cases per 100,000 births (1.3 cases per 100,000 male live births); that for MPS III (Sanfilippo syndrome types A, B and C) as 1.57 cases in 100,000 births; that for MPS IV A (Morquio syndrome) as 0.38 cases in 100,000; and that for MPS VI (Maroteaux-Lamy syndrome) as 0.23 cases per 100,000 births. Two cases of MPS IVB (beta-galactosidase deficiency) have been identified, but no patients with MPS VII or MPS IX. A relatively high number of patients with MPS IIIB, MPS IVA and MPS VI were of Turkish origin. The crude rate for all types of mucopolysaccharidoses is approximately 3.53 cases in 100,000 live births. The cumulative incidence pattern of MPS in Germany was compared with the corresponding rates among other industrial nations obtained from recent literature: the crude cumulative rates for all types of mucopolysaccharidoses (3.4-4.5 in 100,000 live births) were similar among all published populations; however, different frequencies of the various forms of MPS were observed.

An epidemiological study of the mucopolysaccharidoses in Western Australia (WA) using multiple ascertainment sources was carried out and the incidence rate for the period 1969-1996 was estimated. An incidence of approximately 1 in 107,000 live births was obtained for MPS IH (Hurler phenotype); 1 in 320,000 live births (1 in 165,000 male live births) for MPS II (Hunter Syndrome); 1 in 58,000 for MPS III (Sanfilippo Syndrome); 1 in 640,000 for MPS IVA (Morquio Syndrome type A), and 1 in 320,000 for MPS VI (Maroteaux-Lamy Syndrome). The overall incidence for all types of mucopolysaccharidosis was approximately 1 in 29,000 live births. A comparison is made with incidence estimates obtained from other published studies., (Copyright 2003 Wiley-Liss, Inc.)

The mucopolysaccharide (MPS) diseases are a group of inherited, progressive, lysosomal disorders due to deficiencies in various enzymes involved in the lysosomal degradation of cellular glycosaminoglycans (GAG). The six MPS-diseases share clinical features, but each has unique characteristics as well. There is a wide variation in clinical symptomatology even within the same enzyme deficiency. The MPS-diseases are very rare, with only 1-2 affected children born yearly in Sweden (100.000 births). Prenatal diagnosis is available for each condition. Bone-marrow transplantation has been utilized to replace the enzyme deficiency in Hurler's syndrome (MPS I) and Maroteaux-Lamy's syndrome (MPS VI) for the past two decades. When performed before 18-24 months of age in Hurler's syndrome, mental development can be preserved. In this overview we present Swedish incidence and prevalence figures for the different forms of mucopolysaccharidosis, typical symptoms at onset, complications, diagnostic methods and a summary of the present status of research, and finally options for future treatment.

The mucopolysaccharidosis are hereditary diseases. The neurological attack constitutes the principal factor of gravity of these affections. We conducted a retrospective study over a period of 12 years (1988-1999) in the pediatric department of Sfax University Hospital. This study allowed us to observe 11 cases of mucopolysaccharidosis confirmed by an enzymatic proportioning, with 3 cases of Hurler disease (IH), 3 cases of the disease of sanfilippo, (two II A and one III B), 3 cases of the disease of Morquio A (type IVA) and 2 cases of the disease of Maroteaux Lamy (type VI). A sex ratio of 1.75. The parents were cousins in 90% of the cases. The age of revelation ranged between 6 months to 4 years. The clinical examination has found a staturo-pondral delay in 81.8% of the cases, a craniofacial dysmorphy in 100%, deformations of the rachis in 63.6% of the cases, a psychomotor regression in 54.5% of the cases, a medullary compression in 18% of the cases, hepatosplenomegaly in 36.4%, and corneal opacities in 45.4% of the cases. The therapeutic treatment was limited to the symptomatic measures with genetic consulting and antenatal diagnosis.

The bibliographic research online is an useful means of recovering information in all the subjects, particularly in the field of biomedicine. In fact, this instrument allows researchers to get information in a rapid, complete and up-to-date way. The aim of the present review is to describe the usefulness of the bibliographical research online in the field of the genetic osteopathies. These are rare disorders: so, their own rarity makes the bibliographical research online necessary to carry out a large and effective comparison of experiences. The obtained results are amply reported in the manuscript. For instance, we verified that chondrodysplasias are the diseases most represented in the literature, while melorheostosis the disorder less mentioned. Moreover, we evidenced that some hereditary disorders of connective tissue, such as Marfan's syndrome, osteogenesis imperfecta and Ehlers-Danlos syndrome, are strongly influenced by race, sex and age.

Objective: Lysosomal enzyme deficiency results in an accumulation of undegraded material producing structural and functional disorders. Mucopolysaccharidosis is a group of disorders caused by an increase in glycosaminoglycans (GAG) (mucopolysaccharides). Mucopolysaccharidosis, while showing a low incidence, has some clinical manifestations that warrant early diagnosis in order to establish immediate therapeutical action. Although definitive diagnosis is based on quantification of the involved enzymatic activity, it is necessary to have easy to use analytical methods available when there is clinical suspicion of the disease., Patients and Methods: This study was made on a population of 632 clinically normal adolescents and children (one month to 18 years of age). In all cases a partial sample of urine to quantify glycosaminoglycans and creatinine expressed as the index GAG/creatinine (mg/mmol) was collected. In a reduced group of 27 people a 24-hour urine sample was collected. Determination of glycosaminoglycan levels was performed with a colorimetric reaction with 1,9-dimethylmethylene blue (DMB). Optimal condition of pH, wavelength and reaction time were established. The values found to be optimal for quantification were defined as pH 4.0, wavelength 528 nm and a reaction time of five minutes. Intra- and inter-assay coefficients of variation were less than 5%., Results: Validity of the partial urine sample was established by obtaining a linear correlation between the 24 hour urine sample and the partial urine sample with a correlation coefficient of r = 0.89 (p < 0.0001). The results obtained have allowed the establishment of normal values ranging from an index GAG/creatinine of 8.70 mg/mmol in the group aged 1 to 2 years to 1.34 mg/mmol in the group 17 to 18 years of age, with a distribution of intermediate ages adjusted to a logarithmic function. There was a clear difference in the values obtained in urine of patients with clinical suspicion of mucopolysaccharidosis., Conclusions: Modifications in the spectrophotometric method using DMB as a colorant for quantification of glycosaminoglycans are presented. The feasibility, easy application and sensibility of this method, condition required for its widespread use, are confirmed. Normal reference values from a healthy population have been obtained and shown to be age dependent.

An epidemiological study of the mucopolysaccharidoses (MPS) in Northern Ireland using multiple ascertainment sources was carried out and the incidence rate for the period 1958-1985 was estimated. An incidence of approximately 1 in 76,000 live births was obtained for MPS 1H (Hurler phenotype); 1 in 280,000 for MPS 1 H/S (Hurler/Scheie phenotype); 1 in 140,000 live births (1 in 72,000 male live births) for MPS II (Hunter syndrome); 1 in 280,000 for MPS III (Sanfilippo syndrome) and 1 in 76,000 for MPS IV A (Morquio syndrome type A). No cases of MPS IS (Scheie phenotype), MPS IV B (Morquio syndrome type B) or MPS VI (Maroteaux-Lamy syndrome) were ascertained during the study period. Three cases of non-immune hydrops fetalis born to consanguineous parents were thought to be due to beta-glucuronidase deficiency (MPS VII) on the basis of placental histology and enzyme studies on both parents but no living cases of MPS VII were ascertained. The overall incidence for all types of mucopolysaccharidosis was approximately 1 in 25,000 live births. A comparison is made with incidence estimates obtained from other published studies.

Over the last 13 years 2745 patients from all over Greece suspected to have a lysosomal storage disorder were referred to the Institute of Child Health. 1581 of those were suspected of having a mucopolysaccharidosis (MPS). 94 cases (3.42% of the total referrals) were positive: 36 patients with MPS, 6 with mucolipidosis (1 type I, 1 type II and 4 type III) and 3 with mannosidosis. Sanfilippo B was not only the most frequent type III MPS but also the most frequent MPS identified in our study. Sphingolipidoses and other lysosomal disorders were diagnosed in 47 cases and non-lysosomal disorders in 19 cases. In our experience Gaucher disease, Sanfilippo B and Hunter syndrome are the most frequent lysosomal disorders in Greece accounting for 23.4%, 17.0% and 7.6% respectively of all diagnosed cases. 13% of the patients originated from Thessaly including 5/16 Sanfilippo B, 2/3 Morquio B, 2/3 Maroteaux-Lamy, 2/6 Metachromatic leukodystrophy and 2/12 Gaucher type 1.

Urine samples of 200,000 sucklings in 6th-8th month after delivery was analyzed by means of chromatographic screening test for amino acids, sugars and muccopolysacharides. In 1.4% of them persistent and in 51.6% transitory hyperaminoacidurias, in 0.15% persistent and 12.5% transitory melliturias and in 0.05% alcaptonuria were detected. No one case of muccopolysacharidosis was detected. 239 persistent metabolic disorders were detected. These disorders were not possible to detect by means of an obligatory screening test performed on 5th-6th day after delivery from capillary blood. All positive detected cases were verified by detailed metabolic investigation (thin layer, liquid and gas-chromatography).

The MPSs are a heterogeneous group of disorders caused by the deficiency of one of ten lysosomal enzymes and the resultant accumulation of glycosaminoglycans in tissues and organs. The phenotypic variations of each disorder are continuing to be expanded, while the biochemical explanation of these variations needs to be defined. Mucopolysaccharidoses should not be diagnosed solely on clinical grounds, since laboratory confirmation by specific enzyme assay in now available. Prenatal diagnosis is possible for MPSs by amniocentesis. Chorionic villus sampling offers the possibility of first trimester diagnosis. Carrier detection in Hunter's syndrome is not routinely performed, but new procedures may make this needed service more available. No definitive treatment is available. Bone marrow transplantation appears to improve the somatic disease, but correction of the central nervous system disorder may not be possible. The successful development of gene-therapy may in the future provide a means of treatment in MPSs. The management of MPSs can be improved by a better understanding of the natural history of the somatic and central nervous system deterioration in the different disorders. Systematic evaluation and appropriate treatment can lead to an improved quality of life.

A biochemical screening programme for the detection of inherited metabolic disease was carried out on urine and blood samples from inmates of the Alexandra Institute for the mentally retarded, Cape Town. Of the 1087 patients screened, positive results for phenylketonuria were obtained in 3, for cystinuria in 2 and for Hartnup disease in 1. The overall frequency of metabolic disorders was 0,6%. It is evident that genetic metabolic disease as detected by current screening procedures makes only a small contribution to the overall burden of mental retardation.