1. Genotype–phenotype studies in a large cohort of Brazilian patients with Hunter syndrome
- Author
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Luiz Carlos Santana-da-Silva, Carolina Fischinger Moura de Souza, Franciele Barbosa Trapp, Diana Rojas Málaga, Augusto César Cardoso-dos-Santos, Juliana Alves Josahkian, Daniel Almeida do Valle, Dafne Dain Gandelman Horovitz, Sandra Leistner-Segal, Chong Ae Kim, Ana Cecília Menezes de Siqueira, Mara Lúcia Schmitz Ferreira Santos, Diego Santana Chaves Geraldo Miguel, Marcial Francis Galera, Roberto Giugliani, Liane de Rosso Giuliani, Raquel Tavares Boy da Silva, Kristiane Michelin-Tirelli, Maira Graeff Burin, Paula Frassinetti Vasconcelos de Medeiros, Erlane Marques Ribeiro, Alice Brinckmann Oliveira Netto, and Ana Carolina Brusius-Facchin
- Subjects
Male ,Genetics ,Genotype ,business.industry ,Genetic counseling ,Iduronate-2-sulfatase ,Hunter syndrome ,Disease ,medicine.disease ,Phenotype ,Mutation ,Humans ,Medicine ,Missense mutation ,Mucopolysaccharidosis type II ,Allele ,Cognitive decline ,business ,Brazil ,Genetics (clinical) ,Mucopolysaccharidosis II - Abstract
Mucopolysaccharidosis type II (MPS II) is an X-linked inherited disease caused by pathogenic variants in the IDS gene, leading to deficiency of the lysosomal enzyme iduronate-2-sulfatase and consequent widespread storage of glycosaminoglycans, leading to several clinical consequences, with progressive manifestations which most times includes cognitive decline. MPS II has wide allelic and clinical heterogeneity and a complex genotype-phenotype correlation. We evaluated data from 501 Brazilian patients diagnosed with MPS II from 1982 to 2020. We genotyped 280 of these patients (55.9%), which were assigned to 206 different families. Point mutations were present in 70% of our patients, being missense variants the most frequent. We correlated the IDS pathogenic variants identified with the phenotype (neuronophatic or non-neuronopathic). Except for two half-brothers, there was no discordance in the genotype-phenotype correlation among family members, nor among MPS II patients from different families with the same single base-pair substitution variant. Mothers were carriers in 82.0% of the cases. This comprehensive study of the molecular profile of the MPS II cases in Brazil sheds light on the genotype-phenotype correlation and helps the better understanding of the disease and the prediction of its clinical course, enabling the provision of a more refined genetic counseling to the affected families.
- Published
- 2021