1- Unidade de Genética Molecular, Centro de Genética Médica Dr. Jacinto de Magalhães, Centro Hospitalar do Porto, Porto;
2- Departamento de Ciências Biológicas, Laboratório de Bioquímica, Faculdade de Farmácia, Universidade do Porto; Unidade de Genética Molecular, Centro de Genética Médica Dr. Jacinto de Magalhães, Centro Hospitalar do Porto;
3- Serviço de Neurologia Pediátrica, Hospital Dona Estefânia, Centro Hospitalar Lisboa Central EPE, Lisboa;
4- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK;
5- Unidade de Neuropediatria, Hospital de Santa Maria, Centro Hospitalar Lisboa Norte, Lisboa;
6- Consulta de Doenças Neuromusculares, Serviço de Neuropediatria, Centro Hospitalar do Porto;
7- Centro de Desenvolvimento da Criança Luís Borges, Hospital Pediátrico de Coimbra, Centro Hospitalar de Coimbra;
8- Departamento de Ciências Biológicas, Laboratório de Bioquímica, Faculdade de Farmácia, Universidade do Porto; Instituto de Biologia Molecular e Celular, Universidade do Porto
Journal Human Genetics. 2014 Aug;59(8):454-64
Molecular characterization of patients with Duchenne or Becker muscular dystrophies is essential for establishing a differential diagnosis, allowing appropriate clinical follow-up, patient management and genetic counseling. In light of the recent mutation-based therapeutic approaches, DMD gene analysis has gained further relevance. Owing to the size and complexity of the DMD gene and the diversity of mutation types, molecular analysis is not always a straightforward task requiring the combination of several methodologies. Our national genetic diagnostic service genetically characterized 308 dystrophinopathy patients (284 unrelated families), leading to the identification of 175 distinct mutations, including 39 unpublished variants. These studies revealed several potential diagnostic pitfalls (because of technical limitations or related with DMD's genetic heterogeneity) that may be overlooked even considering the international disease-specific diagnostic guidelines. Comprehensive analysis involved expression studies at the mRNA level, the identification of splicing changes and ultimately providing evidence for apparent exceptions to the reading-frame rule. Besides increasing the mutation detection rate, this detailed molecular characterization is indispensable for the identification of suitable candidates for the new mutation-centered therapies. As patient registries are internationally recognized as essential for clinical trial recruitment, this led us to develop the Portuguese Duchenne and Becker Muscular Dystrophy registry in collaboration with the Translational Research in Europe-Assessment and Treatment of Neuromuscular Diseases network.
Palavras Chave: Distrofia muscular Duchenne, genotipo