Tehran University of Medical Sciences

Science Communicator Platform

Stay connected! Follow us on X network (Twitter):
Share this content! On (X network) By
Diagnosing Mucopolysaccharidosis Type Iv a by the Fluorometric Assay of N-Acetylgalactosamine-6-Sulfate Sulfatase Activity Publisher



Shams S1, 2, 3 ; Barazandeh Tehrani M4 ; Civallero G5 ; Minookherad K4 ; Giugliani R5, 6 ; Setoodeh A7 ; Ashtiani MTH1, 2
Authors
Show Affiliations
Authors Affiliations
  1. 1. Tehran University of Medical Sciences, Children's Medical Center, Pediatrics Center of Excellence, Tehran, Iran
  2. 2. Tehran University of Medical Sciences, Department of Pathology, Tehran, Iran
  3. 3. Tehran University of Medical Sciences, Pediatric Urology Research Center, Tehran, Iran
  4. 4. Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Department of Medicinal Chemistry, Tehran, Iran
  5. 5. Medical Genetics Service, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil
  6. 6. Federal University of Rio Grande do Sul, Department of Genetics, Porto Alegre, Brazil
  7. 7. Pediatrics Center of Excellence, Tehran University of Medical Sciences, Division of Pediatrics Endocrinology
  8. 8. Children's Medical Center, Tehran, Iran

Source: Journal of Diabetes and Metabolic Disorders Published:2017


Abstract

Background: Mucopolysaccharidosis type IVA, also known as Morquio A or MPS IV A, is an autosomal recessive disease caused by the deficiency of the lysosomal enzyme N-acetylgalactosamine-6-sulfate sulfatase (GALNS). The loss of GALNS activity leads to the impaired breakdown of glycosaminoglycans (GAGs) keratan sulfate and chondroitin-6-sulfate. The accumulation of GAGs results in multiple organ damage. The accurate and early diagnosis of this disorder helps enhance the effectiveness of the treatment. The present study uses a pre-designed protocol for testing GALNS activity in the leukocytes of Iranian patients with MPS IV A and their parents and compares it with healthy controls. Methods: Patients with MPS IVA previously diagnosed through the measurement of enzyme activity or genetic analysis entered the study. Leukocytes were obtained from the heparinized blood of the participants. The GALNS activity was measured by a fluorometric method using 4-methylumbelliferyl-β-D-galactoside-6-sulfate (4MU-G6S) as the substrate and proper buffer solutions and calibrators. Results: The GALNS activity (nmol/17 h/mg protein) was reported as 0-7.4 in the MPSIV A patients, as 19.85-93.7 in their parents and as 38.4-164 in the healthy controls. Statistically significant differences were observed between the three groups in terms of enzyme activity. There were no significant differences in enzyme activity by age. The female subjects in both the patient and parents groups showed lower enzyme activity compared to the male subjects. Conclusion: The fluorometric method was validated for the measurement of GALNS activity in leukocyte samples and identifying Iranian patients with MPS IV A. © 2017 The Author(s).