Muccopolysaccharidosis Type II, Two Novel Mutations

Sedky, Nouran Mohamed; Fateen, Ekram; Khalil, Mona Salem; Ibrahim, Nahed Mohamed; Ibrahim, Mona Mohamed; Aglan, Mona; Hassan, Heba Amin; Essawi, Mona

doi:10.21608/mxe.2025.362691.1037

Muccopolysaccharidosis Type II, Two Novel Mutations

Document Type : Original Article

Authors

¹ Medical Molecular Genetics, National Research Centre, Cairo, Egypt

² National Research Centre

³ Clinical and Chemical Chemistry, Faculty of medicine, Ksr Eleny Cairo University, Cairo, Egypt

⁴ Biochemical Genetics, Division of Human Genetics and Genome Research, National Research Centre, Dokki12311, Cairo, Egypt

10.21608/mxe.2025.362691.1037

Abstract

Background: Mucopolysaccharidosis type II (Hunter syndrome; MPS II) is an X-linked lysosomal disorder caused by mutations detected in the gene that controls production of the enzyme iduronate-2-sulfatase (IDS). MPS II is considered to be a rare disease worldwide, with an incidence of 0.3–0.7 per 100,000 among live births. The primary defect of the disease is caused by a mutation on the IDS gene which disrupts the activity of the IDS lysosomal enzyme. The enzyme IDS catalyzes one of the steps in the catabolism of the glycosaminoglycans (GAGs), leading to accumulation of both heparan and dermatan sulphate in different tissues and organs of the body with excretion of large amounts of them in the urine. The clinical spectrum of MPS II includes mild, intermediate, and severe variants affecting mainly the connective tissues, skeletal system, brain, liver and spleen. To date, 792 variants have been reported by the HGMD associated with MPS type II have been identified.
This study was done for two Egyptian male patients with MPS type 2 which revealed 2 novel mutations in the two different patients with successful segregation of their mothers aligning with X-linked recessive mode of inheritance. We recommend a genotype phenotype correlation using larger cohorts of patients in the future studies.

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