MOLECULAR GENETIC ANALYSIS OF MPS I PATIENTS AT THE NATIONAL PEDIATRIC HOSPITAL
Main Article Content
Abstract
Mucopolysaccharidosis type I (MPS I) is a rare lysosomal storage disorder caused by a deficiency of the enzyme α‑L‑iduronidase, leading to the accumulation of glycosaminoglycans (GAG) in tissues and multiple organ damage. This study reports three cases of MPS I diagnosed at the National Pediatric Hospital, based on clinical, paraclinical evaluations, quantitative enzyme assay, and molecular genetic analysis of the IDUA gene. All patients exhibited typical clinical features such as coarse facial features, corneal clouding, joint stiffness, spinal deformity, and hearing loss, along with severely reduced enzyme activity (<3% of normal). Genetic analysis identified three homozygous variants: c.536C>G (p.Thr179Arg – pathogenic), c.1190-10C>A (pathogenic) and c.792+1_792+5del (likely pathogenic, LPV). Family genetic analysis confirmed an autosomal recessive inheritance pattern with a recurrence risk of 25% per pregnancy. Comparison with international studies suggests that the c.1190-10C>A variant may represent a founder mutation in the Vietnamese population. This research expands the clinical and molecular data on MPS I in Vietnam and provides valuable information for genetic counseling and early therapeutic interventions.
Article Details
Keywords
MPS I, IDUA, alpha-L-iduronidase, molecular genetics, autosomal recessive, genetic counseling, Vietnamese patients
References


2. Beck M, Arn P, Giugliani R, et al. The natural history of MPS I: global perspectives from the MPS I Registry. Genet Med. 2014;16(10):759-765. doi:10.1038/gim.2014.25


3. Can NTB, Tran DM, Bui TP, et al. Molecular Analysis of Vietnamese Patients with Mucopolysaccharidosis Type I. Life. 2021;11(11): 1162. doi:10.3390/life11111162


4. Muenzer J, al JEW et. Mucopolysaccharidosis I: Management and Treatment Guidelines. PEDIATRICS. 2009;123(1):19-29.

5. Wang RY, Bodamer OA, Watson MS, Wilcox WR. Lysosomal storage diseases: Diagnostic confirmation and management of presymptomatic individuals. Genet Med. 2011;13:457-484. doi:10.1097/GIM.0b013e3182205f1a


6. NM_000203.5:c.792+1_792+5del Deletion (5bp) | hg38. https://varsome.com/variant/ hg38/NM_000203.5%3Ac.792%2B1_792%2B5del?annotation-mode=germline. Accessed April 10, 2025.
