scholarly journals Mucopolysaccharidosis IVA: Diagnosis, Treatment, and Management

2020 ◽  
Vol 21 (4) ◽  
pp. 1517 ◽  
Author(s):  
Kazuki Sawamoto ◽  
José Álvarez González ◽  
Matthew Piechnik ◽  
Francisco Otero ◽  
Maria Couce ◽  
...  

Mucopolysaccharidosis type IVA (MPS IVA, or Morquio syndrome type A) is an inherited metabolic lysosomal disease caused by the deficiency of the N-acetylglucosamine-6-sulfate sulfatase enzyme. The deficiency of this enzyme accumulates the specific glycosaminoglycans (GAG), keratan sulfate, and chondroitin-6-sulfate mainly in bone, cartilage, and its extracellular matrix. GAG accumulation in these lesions leads to unique skeletal dysplasia in MPS IVA patients. Clinical, radiographic, and biochemical tests are needed to complete the diagnosis of MPS IVA since some clinical characteristics in MPS IVA are overlapped with other disorders. Early and accurate diagnosis is vital to optimizing patient management, which provides a better quality of life and prolonged life-time in MPS IVA patients. Currently, enzyme replacement therapy (ERT) and hematopoietic stem cell transplantation (HSCT) are available for patients with MPS IVA. However, ERT and HSCT do not have enough impact on bone and cartilage lesions in patients with MPS IVA. Penetrating the deficient enzyme into an avascular lesion remains an unmet challenge, and several innovative therapies are under development in a preclinical study. In this review article, we comprehensively describe the current diagnosis, treatment, and management for MPS IVA. We also illustrate developing future therapies focused on the improvement of skeletal dysplasia in MPS IVA.

2021 ◽  
Vol 22 (11) ◽  
pp. 6165
Author(s):  
José V. Álvarez ◽  
Susana B. Bravo ◽  
María Pilar Chantada-Vázquez ◽  
Sofía Barbosa-Gouveia ◽  
Cristóbal Colón ◽  
...  

Mucopolysaccharidosis type IVA (MPS IVA) is a lysosomal disease caused by mutations in the gene encoding the enzymeN-acetylgalactosamine-6-sulfate sulfatase (GALNS), and is characterized by systemic skeletal dysplasia due to excessive storage of keratan sulfate (KS) and chondroitin-6-sulfate in chondrocytes. Although improvements in the activity of daily living and endurance tests have been achieved with enzyme replacement therapy (ERT) with recombinant human GALNS, recovery of bone lesions and bone growth in MPS IVA has not been demonstrated to date. Moreover, no correlation has been described between therapeutic efficacy and urine levels of KS, which accumulates in MPS IVA patients. The objective of this study was to assess the validity of potential biomarkers proposed by other authors and to identify new biomarkers. To identify candidate biomarkers of this disease, we analyzed plasma samples from healthy controls (n=6) and from untreated (n=8) and ERT-treated (n=5, sampled before and after treatment) MPS IVA patients using both qualitative and quantitative proteomics analyses. The qualitative proteomics approach analyzed the proteomic profile of the different study groups. In the quantitative analysis, we identified/quantified 215 proteins after comparing healthy control untreated, ERT-treated MPSIVA patients. We selected a group of proteins that were dysregulated in MPS IVA patients. We identified four potential protein biomarkers, all of which may influence bone and cartilage metabolism: fetuin-A, vitronectin, alpha-1antitrypsin, and clusterin. Further studies of cartilage and bone samples from MPS IVA patients will be required to verify the validity of these proteins as potential biomarkers of MPS IVA.


Glycobiology ◽  
2020 ◽  
Vol 30 (7) ◽  
pp. 433-445
Author(s):  
Roger Lawrence ◽  
Heather Prill ◽  
Preejith P Vachali ◽  
Evan G Adintori ◽  
Greg de Hart ◽  
...  

Abstract Morquio syndrome type A, also known as MPS IVA, is a rare autosomal recessive disorder caused by deficiency of N-acetylgalactosamine-6-sulfatase, a lysosomal hydrolase critical in the degradation of keratan sulfate (KS) and chondroitin sulfate (CS). The CS that accumulates in MPS IVA patients has a disease-specific nonreducing end (NRE) terminating with N-acetyl-D-galactosamine 6-sulfate, which can be specifically quantified after enzymatic depolymerization of CS polysaccharide chains. The abundance of N-acetyl-D-galactosamine 6-sulfate over other possible NRE structures is diagnostic for MPS IVA. Here, we describe an assay for the liberation and measurement of N-acetyl-D-galactosamine 6-sulfate and explore its application to MPS IVA patient samples in pilot studies examining disease detection, effects of age and treatment with enzyme-replacement therapy. This assay complements the existing urinary KS assay by quantifying CS-derived substrates, which represent a distinct biochemical aspect of MPS IVA. A more complete understanding of the disease could help to more definitively detect disease across age ranges and more completely measure the pharmacodynamic efficacy of therapies. Larger studies will be needed to clarify the potential value of this CS-derived substrate to manage disease in MPS IVA patients.


2020 ◽  
Vol 22 (1) ◽  
pp. 226
Author(s):  
Víctor J. Álvarez ◽  
Susana B. Bravo ◽  
Maria Pilar Chantada-Vazquez ◽  
Cristóbal Colón ◽  
María J. De Castro ◽  
...  

Mucopolysaccharidosis type IVA (MPS IVA) is a lysosomal storage disease caused by mutations in the N-acetylgalactosamine-6-sulfatase (GALNS) gene. Skeletal dysplasia and the related clinical features of MPS IVA are caused by disruption of the cartilage and its extracellular matrix, leading to a growth imbalance. Enzyme replacement therapy (ERT) with recombinant human GALNS has yielded positive results in activity of daily living and endurance tests. However, no data have demonstrated improvements in bone lesions and bone grow thin MPS IVA after ERT, and there is no correlation between therapeutic efficacy and urine levels of keratan sulfate, which accumulates in MPS IVA patients. Using qualitative and quantitative proteomics approaches, we analyzed leukocyte samples from healthy controls (n = 6) and from untreated (n = 5) and ERT-treated (n = 8, sampled before and after treatment) MPS IVA patients to identify potential biomarkers of disease. Out of 690 proteins identified in leukocytes, we selected a group of proteins that were dysregulated in MPS IVA patients with ERT. From these, we identified four potential protein biomarkers, all of which may influence bone and cartilage metabolism: lactotransferrin, coronin 1A, neutral alpha-glucosidase AB, and vitronectin. Further studies of cartilage and bone alterations in MPS IVA will be required to verify the validity of these proteins as potential biomarkers of MPS IVA.


2019 ◽  
Vol 20 (17) ◽  
pp. 4139 ◽  
Author(s):  
Kazuki Sawamoto ◽  
Shunji Tomatsu

Mucopolysaccharidosis IVA (MPS IVA) is caused by a deficiency of the lysosomal enzyme N-acetylgalactosamine-6-sulfate sulfatase (GALNS). Conventional enzyme replacement therapy (ERT) is approved for MPS IVA. However, the fact that the infused enzyme cannot penetrate avascular lesions in cartilage leads to minimal impact on the bone lesion. Moreover, short half-life, high cost, instability, and narrow optimal pH range remain unmet challenges in ERT. Thermostable keratanase, endo-β-N-acetylglucosaminidase, has a unique character of a wide optimal pH range of pH 5.0–7.0. We hypothesized that this endoglycosidase degrades keratan sulfate (KS) polymer in circulating blood and, therefore, ameliorates the accumulation of KS in multiple tissues. We propose a novel approach, Substrate Degradation Enzyme Therapy (SDET), to treat bone lesion of MPS IVA. We assessed the effect of thermostable keratanase on blood KS level and bone pathology using Galns knock-out MPS IVA mice. After a single administration of 2 U/kg (= 0.2 mg/kg) of the enzyme at 8 weeks of age via intravenous injection, the level of serum KS was significantly decreased to normal range level, and this suppression was maintained for at least 4 weeks. We administered 2 U/kg of the enzyme to MPS IVA mice every fourth week for 12 weeks (total of 3 times) at newborns or 8 weeks of age. After a third injection, serum mono-sulfated KS levels were kept low for 4 weeks, similar to that in control mice, and at 12 weeks, bone pathology was markedly improved when SDET started at newborns, compared with untreated MPS IVA mice. Overall, thermostable keratanase reduces the level of KS in blood and provides a positive impact on cartilage lesions, demonstrating that SDET is a novel therapeutic approach to MPS IVA.


2019 ◽  
Vol 20 (18) ◽  
pp. 4610 ◽  
Author(s):  
J. Víctor Álvarez ◽  
Susana B. Bravo ◽  
María García-Vence ◽  
María J. De Castro ◽  
Asteria Luzardo ◽  
...  

Morquio A syndrome, or mucopolysaccharidosis type IVA (MPS IVA), is a lysosomal storage disease due to mutations in the N-acetylgalactosamine-6-sulfatase (GALNS) gene. Systemic skeletal dysplasia and the related clinical features of MPS IVA are due to disruption of cartilage and its extracellular matrix, leading to an imbalance of growth. Enzyme replacement therapy (ERT) with recombinant human GALNS, alpha elosulfase, provides a systemic treatment. However, this therapy has a limited impact on skeletal dysplasia because the infused enzyme cannot penetrate cartilage and bone. Therefore, an alternative therapeutic approach to reach the cartilage is an unmet challenge. We have developed a new drug delivery system based on a nanostructure lipid carrier with the capacity to immobilize enzymes used for ERT and to target the lysosomes. This study aimed to assess the effect of the encapsulated enzyme in this new delivery system, using in vitro proteomic technology. We found a greater internalization of the enzyme carried by nanoparticles inside the cells and an improvement of cellular protein routes previously impaired by the disease, compared with conventional ERT. This is the first qualitative and quantitative proteomic assay that demonstrates the advantages of a new delivery system to improve the MPS IVA ERT.


2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Albina Tummolo ◽  
Orazio Gabrielli ◽  
Alberto Gaeta ◽  
Maristella Masciopinto ◽  
Lucia Zampini ◽  
...  

Morquio A syndrome (Mucopolysaccharidosis type IVA) (MPS IVA) is a rare inherited metabolic disorder characterized by the defective degradation of keratan sulfate and chondroitin-6-sulfate. Classically, MPS IVA patients present with severe multisystemic involvement and have a short life expectancy. Attenuated forms with clinical features limited to minor skeletal abnormalities and short stature have also been described, sometimes associated to an early-onset osteoporotic phenotype. No treatment with allogenic bone marrow transplantation or gene therapy is currently available for Morquio A syndrome, and enzyme replacement therapy is under evaluation. We report a case of MPS IVA, who manifested tardily attenuated phenotype and significant bone mass reduction, which was treated with a bisphosphonate (BPN), resulting in an improvement of X-ray skeletal aspects and functional bone performance. We suggest that the use of bisphosphonates may be an interesting supportive therapeutic option for Morquio A patients with osteoporotic phenotype, but further studies involving more patients are necessary to confirm our findings.


2021 ◽  
Vol 14 ◽  
pp. 117954762199940
Author(s):  
Eric Goldman ◽  
Angela Vu ◽  
Kelly Dietz ◽  
Stefani N Thomas

Mucopolysaccharidosis IVA (MPS IVA) is a rare autosomal recessive lysosomal storage disorder resulting from N-acetylgalactosamine-6-sulfatase (GALNS) deficiency that occurs in approximately 1 in 76 000 to 1 in 640 000 live births. Given that the diagnosis of MPS IVA relies heavily on the results of initial urine glycosaminoglycan (GAG) screening, cases that present with falsely normal urine GAG concentrations can delay the diagnosis and follow-up care for patients. This case study follows a patient diagnosed with MPS IVA at 9 months of age based on relation to a consanguineous 3-year-old sibling with MPS IVA and the use of direct enzyme activity analysis. Details regarding skeletal presentation and identification of genetic variants are presented along with data on follow-up urinary GAG monitoring during treatment with enzyme replacement therapy and treatment for a growth hormone disorder.


Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 189
Author(s):  
Christiane S. Hampe ◽  
Jacob Wesley ◽  
Troy C. Lund ◽  
Paul J. Orchard ◽  
Lynda E. Polgreen ◽  
...  

Mucopolysaccharidosis type I (MPS I) is a lysosomal disease, caused by a deficiency of the enzyme alpha-L-iduronidase (IDUA). IDUA catalyzes the degradation of the glycosaminoglycans dermatan and heparan sulfate (DS and HS, respectively). Lack of the enzyme leads to pathologic accumulation of undegraded HS and DS with subsequent disease manifestations in multiple organs. The disease can be divided into severe (Hurler syndrome) and attenuated (Hurler-Scheie, Scheie) forms. Currently approved treatments consist of enzyme replacement therapy (ERT) and/or hematopoietic stem cell transplantation (HSCT). Patients with attenuated disease are often treated with ERT alone, while the recommended therapy for patients with Hurler syndrome consists of HSCT. While these treatments significantly improve disease manifestations and prolong life, a considerable burden of disease remains. Notably, treatment can partially prevent, but not significantly improve, clinical manifestations, necessitating early diagnosis of disease and commencement of treatment. This review discusses these standard therapies and their impact on common disease manifestations in patients with MPS I. Where relevant, results of animal models of MPS I will be included. Finally, we highlight alternative and emerging treatments for the most common disease manifestations.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Jane E. Potter ◽  
Gemma Petts ◽  
Arunabha Ghosh ◽  
Fiona J. White ◽  
Jane L. Kinsella ◽  
...  

Abstract Background Wolman disease is a rare, lysosomal storage disorder in which biallelic variants in the LIPA gene result in reduced or complete lack of lysosomal acid lipase. The accumulation of the substrates; cholesterol esters and triglycerides, significantly impacts cellular function. Untreated patients die within the first 12 months of life. Clinically, patients present severely malnourished, with diarrhoea and hepatosplenomegaly, many have an inflammatory phenotype, including with hemophagocytic lymphohistiocytosis (HLH). Hematopoietic stem cell transplant (HCT) had been historically the only treatment available but has a high procedure-related mortality because of disease progression and disease-associated morbidities. More recently, enzyme replacement therapy (ERT) with dietary substrate reduction (DSR) has significantly improved patient survival. However, ERT is life long, expensive and its utility is limited by anti-drug antibodies (ADA) and the need for central venous access. Results We describe five Wolman disease patients diagnosed in infancy that were treated at Royal Manchester Children's Hospital receiving ERT with DSR then HCT—multimodal therapy. In 3/5 an initial response to ERT was attenuated by ADA with associated clinical and laboratory features of deterioration. 1/5 developed anaphylaxis to ERT and the other patient died post HCT with ongoing HLH. All patients received allogeneic HCT. 4/5 patients are alive, and both disease phenotype and laboratory parameters are improved compared to when they were on ERT alone. The gastrointestinal symptoms are particularly improved after HCT, with reduced diarrhoea and vomiting. This allows gradual structured normalisation of diet with improved tolerance of dietary fat. Histologically there are reduced cholesterol clefts, fewer foamy macrophages and an improved villous structure. Disease biomarkers also show improvement with ERT, immunotherapy and HCT. Three patients have mixed chimerism after HCT, indicating a likely engraftment-defect in this condition. Conclusion We describe combined ERT, DSR and HCT, multimodal treatment for Wolman disease. ERT and DSR stabilises the sick infant and reduces the formerly described prohibitively high, transplant-associated mortality in this condition. HCT abrogates the problems of ERT, namely attenuating ADA, the need for continuing venous access, and continuing high cost drug treatment. HCT also brings improved efficacy, particularly evident in improved gastrointestinal function and histology. Multimodal therapy should be considered a new paradigm of treatment for Wolman disease patients where there is an attenuated response to ERT, and for all patients where there is a well-matched transplant donor, in order to improve long term gut function, tolerance of a normal diet and quality of life.


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