Es-Said Sabir1, Karima Lafhal1, Aicha Ezoubeiri2, Imane Harkati2, Safia Sbyea1, Luis Aldámiz-Echevarría3, Fernando Andrade3, Mohammed Ait Babram4, Fadl Mrabih Rabou Maoulainine5, Ghizlane Draiss6, Noureddine Rada6, Mohammed Bouskraoui6, Abdallah Karim7, Naima Fdil1. 1. Metabolics Platform, Biochemistry Laboratory, Faculty of Medicine, Cadi Ayad University, Marrakech, Morocco. 2. Medical Biology Laboratory - Biochemistry Unit, Ibn Tofail Hospital, CHU Mohamed VI of Marrakech, Marrakech, Morocco. 3. Metabolomics Platform, Biocruces Bizkaia Health Research Institute, Clinical Linked Group to CIBER of Rare Diseases (CIBERER), Barakaldo, Spain. 4. Department of Mathematics, Faculty of Science and Technology, Cadi Ayad University, Marrakech, Morocco. 5. Neonatal Intensive Care Department, Team for Childhood, Health and Development, Marrakesh Faculty of Medicine, Mohammed VI University Hospital and Research, Cadi Ayad University, Marrakech, Morocco. 6. Department of Pediatrics A, Faculty of Medicine and Pharmacy, Mohammed VI University Hospital, Cadi Ayad University, Marrakech, Morocco. 7. Laboratory of Coordination Chemistry, Faculty of Sciences Semlalia, Cadi Ayad University, Marrakech, Morocco.
Abstract
BACKGROUND: Mucopolysaccharidoses (MPS), a group of inherited metabolic disorders characterized by the accumulation of glycosaminoglycans, can be diagnosed early through newborn screening programs. Establishing newborn screening in Morocco is a challenging task for multiple economic and social reasons. Screening in a Moroccan population using 1,9-dimethylmethylene blue urinary glycosaminoglycan (GAG) assays may allow for an earlier diagnosis of MPS. We studied the feasibility of implementing screening in Moroccan children as an alternative to national newborn screening. We determined the reference ranges for GAGs in the Moroccan population, their stability during transport, the effectiveness of this test as a screening procedure for MPS in patients, and its use as a screening test for MPS in the Imssouane region, where the rate of consanguineous marriage is 38%. METHODS: Using dimethylmethylene blue assays, urine samples of 47 MPS patients were analyzed, together with urine samples from healthy controls (n = 368, age ranging from 1 month to 25 years), and from Imssouane region children (n = 350, age ranging from 6 months to 24 month). Precision, linearity, recovery, limits, and stability were tested. RESULTS: Urinary GAGs reference values are age and ethnicity dependent. The validation parameters established displayed great precision and accuracy leading to recoveries according to internationally accepted values for bioanalytical methods. Urinary GAGs were stable for a maximum of 7 weeks at 40 °C. Screening of Imssouane children resulted in the detection of a 6-month-old child, diagnosed with MPS I. CONCLUSIONS: Our results demonstrate the usefulness of quantifying glycosaminoglycans for early screening of MPS.
BACKGROUND: Mucopolysaccharidoses (MPS), a group of inherited metabolic disorders characterized by the accumulation of glycosaminoglycans, can be diagnosed early through newborn screening programs. Establishing newborn screening in Morocco is a challenging task for multiple economic and social reasons. Screening in a Moroccan population using 1,9-dimethylmethylene blue urinary glycosaminoglycan (GAG) assays may allow for an earlier diagnosis of MPS. We studied the feasibility of implementing screening in Moroccan children as an alternative to national newborn screening. We determined the reference ranges for GAGs in the Moroccan population, their stability during transport, the effectiveness of this test as a screening procedure for MPS in patients, and its use as a screening test for MPS in the Imssouane region, where the rate of consanguineous marriage is 38%. METHODS: Using dimethylmethylene blue assays, urine samples of 47 MPSpatients were analyzed, together with urine samples from healthy controls (n = 368, age ranging from 1 month to 25 years), and from Imssouane region children (n = 350, age ranging from 6 months to 24 month). Precision, linearity, recovery, limits, and stability were tested. RESULTS: Urinary GAGs reference values are age and ethnicity dependent. The validation parameters established displayed great precision and accuracy leading to recoveries according to internationally accepted values for bioanalytical methods. Urinary GAGs were stable for a maximum of 7 weeks at 40 °C. Screening of Imssouane children resulted in the detection of a 6-month-old child, diagnosed with MPS I. CONCLUSIONS: Our results demonstrate the usefulness of quantifying glycosaminoglycans for early screening of MPS.
Authors: Luise Sophie Ammer; Sandra Pohl; Sandra Rafaela Breyer; Charlotte Aries; Jonas Denecke; Anna Perez; Martin Petzoldt; Johanna Schrum; Ingo Müller; Nicole Maria Muschol Journal: Mol Genet Metab Rep Date: 2021-01-14