Genetic Heterogeneity of Iduronate-2-Sulfatase in Children Diagnosed with Mucopolysaccharidosis Type II in Azerbaijan

Abstract

Background: Mucopolysaccharidosis (MPS) is a rare hereditary disease of lysosomal storage with an X-linked recessive inheritance type, and Hunter's disease is a fairly rare manifestation of mucopolysaccharidosis type II. Objectives: In the present study, a modern molecular-genetic diagnostic method such as New Generation Sequencing (NGS) was used for the first time to identify iduronate-2-sulfatase (IDS) mutations in the Azerbaijan population. Methods: In four patients with similar clinical manifestations of Hunter’s disease, we carried out enzyme analysis for all MPS types: MPS I, MPS II, MPS III, MPS IV, and MPS VI. Results: All four probands observed iduronate-2-sulfatase activity deficiency that corresponded with MPS type II. Molecular genetic analysis of the IDS gene identified three different mutations: -1215del, 1106 (С-G), and 322 (G-T). In consequence of those mutations: - 1215del, 1106 (С- G), and 322 (G-T) appear correspondent amino acid substitution in synthesized protein - enzyme composition: Leu406Phefs*34, Asp358Leu, Tyr108Asp, relatively. Conclusions: Taking into account the reproductive age of the parents of affected children, further preventive prenatal studies are recommended in the families of the index patients.