Clinical characteristics and genotypes of 201 patients with mucopolysaccharidosis type II in China: A retrospective, observational study

Clin Genet. 2023 Jun;103(6):655-662. doi: 10.1111/cge.14329.

PMID: 36945845

Lin Zhong, Xiaolan Gao, Yu Wang

Highlights: This study aimed to characterize the clinical characteristics and genotypes of the largest cohort of Chinese patients with mucopolysaccharidosis type II (MPS II).

Abstract

Background: An X-linked recessive lysosomal storage disease called mucopolysaccharidosis type II (MPS II) is brought on by a disease-associated variant in the IDS gene, which codes for the enzyme iduronate 2-sulfatase (IDS).

Objective: In order to better understand how MPS II develops naturally, the clinical characteristics and genotypes of the largest cohort of Chinese individuals with the disease are characterized.

Results: Included were patients who had verified MPS II and weren't receiving treatment. Patients above the age of 6 without neurological impairment were defined as having attenuated disease, whereas those with neurological impairment were classed as having severe disease. 78.1 percent of the 201 male patients had severe MPS II. In 94.3% of patients, cognitive decline started before the age of 6 years. 37 unique IDS variants out of 122 total were found. Only IDS-IDS2 recombination was substantially more frequent in severe MPS II compared to attenuated MPS II among the large gene alteration types found (P = 0.032). The knowledge of the correlations between genotype and phenotype may be improved by some recognized point variants.

Conclusion: In conclusion, this study demonstrated that only patients older than 6 years should have their condition classified as attenuated. Our research contributes to the understanding of the genotype-phenotype relationship, aids in the diagnosis, and predicts the prognosis.

Keywords: genotype-phenotype correlation, hunter syndrome, iduronate 2-sulfatase gene, mucopolysaccharidosis II