Implementation of molecular techniques for the neonatal sreening of spinal muscular atrophy

• Autor(a) principal: Carneiro, Paula Renata Oliveira
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.22/21751
• topic: Spinal muscular atrophy; Newborn screening; Real-time Polimerase chain reaction

Spinal muscular aptrophy (SMA) is neurodegenerative disease mainly caused by the homozygous deletion of the functional tolemeric survival motor neuron 1 gene (SMN1) exon 7. This absence causes a lack of the ubiquitous SMN protein wich, in turn, selectively destroys alfa motor neurons. Due to the disease severity, i tis the leading genetic cause of infant death. The copy number of the centromeric SMN2 gene has na inverse correlation with the phenotype. SMA is currently classified in 5 types – Type 0 (lethal in womb or in th first weeks of life), Type 1 (that counts for the majority of cases), Type 2 (children can sit alone), Type 3 (children can walk independently) and Type 4 (mildest from that appears in dults). Diagnosis i only made when symptoms arise and by that time motor neurons are already irreversibly loss. Three therapies are now available but they are most effective in the asymptomatic phase. To achieve this objective, the strategy is to include SMA in the panel of diseases screened in the Neonatal Screening Programs. In this sense, we describe the implementation of na assay, based on reagentes prepared in house, that detects the absence of exon7 of the SMN1gene through the real-time polymerase chain reaction (qPCR) technique, adapted to Neonatal Screening. Samples used were from the dried blood spots of the already implemented Guthrie cards on the newborn screening. This method is a reliable, simple and affordable way to screen for this lethal disease.