SciELO - Scientific Electronic Library Online

 
vol.23 suppl.1Clinical, biochemical and molecular studies: stepwise to achieve diagnosis of fabry diseaseA adrenoleucodistrofia ligada ao cromossoma X em portugal índice de autoresíndice de assuntosPesquisa de artigos
Home Pagelista alfabética de periódicos  

Serviços Personalizados

Journal

Artigo

Indicadores

Links relacionados

  • Não possue artigos similaresSimilares em SciELO

Compartilhar


Nascer e Crescer

versão impressa ISSN 0872-0754

Nascer e Crescer vol.23  supl.1 Porto mar. 2014

 

POSTER ABSTRACTS / RESUMOS DE POSTERS

 

P-17

Hunter syndrome, the most prevalent mucopolysaccharidosis in portugal

 

 

Sónia RochaI; Carla CaseiroI; Isaura RibeiroI; Eugénia PintoI; Célia FerreiraI; Helena RibeiroI; Elisabete SilvaI; Fernanda PintoI; Sara PachecoI; Domingos SousaI; Francisco LaranjeiraI; Lúcia LacerdaI

IUnidade de Bioquímica Genética, Centro de Genética Médica Doutor Jacinto Magalhães, Centro Hospitalar do Porto E.P.E., Porto, Portugal

sonia.rocha@chporto.min-saude.pt

 

 

Introduction: Lysosomal  storage  diseases  (LSD)  is a group of rare diseases which involves more than 50 inherited metabolic diseases, being Hunter disease Mucopolysaccharidosis type II (MPS  II)-  MIM  309900, an inherited X-linked LSD. MPS II is due to iduronate-2-sulfatase (IDS) enzymatic deficiency, that leads to impaired hydrolyses of terminal iduronate 2-sulfate esters into heparan and dermatan sulfate. More than 300 mutations have been reported in IDS gene, located at Xq28, and MPS II has an estimated prevalence of 1 in  170  000  male  live  births. As well as in other MPS disorders, there is a wide clinical variability, ranging from mild to severe clinical phenotype. The availability of enzyme replacement therapy improves many of the symptoms and signs of the disease.

Aim: To report the MPS II prevalence in the Portuguese population and present data from enzyme replacement in treated patients.

Methods: MPS II diagnosis as a three steps analytical approach: screening for quantitative and qualitative urinary glycosaminoglicans accumulation, definitive diagnosis iduronate-sulphatase activity determination in blood or cultured fibroblasts and genotype identification by IDS gene sequencing to ascertain causal mutations.

Results: MPS II is the most prevalent MPS in Portugal. Since 1984, 33 index patients, belonging to 28  families, were diagnosed and 8 of them were submitted to enzyme replacement therapy. Apparently clinical variability among MPS II patients is a mere reflection of molecular heterogeneity, as patients with an IDS gene complete deletion seem to have a more severe form of the disease. A more profound clinical evaluation is required as, until now, no female patients have diagnosed.

Conclusions: Some LSD have a overlapping clinical phenotype with MPS. However, clinicians faced with male affected members in different family generations, should consider MPS II as the first hypothesis in the differential diagnosis. Once the genotype has been ascertained, genetic counseling should include female carrier identification in the affected families. Although the incidence of these genetic diseases is quite low, their combined incidence is 1 in 7000 births, which is in the range considered to be feasible for a newborn screening.

Creative Commons License Todo o conteúdo deste periódico, exceto onde está identificado, está licenciado sob uma Licença Creative Commons