Spinal muscular atrophy (SMA) is one of the leading genetic causes of infant mortality. Caused by a defect in the SMN1 gene, it is characterized by degeneration of the motor neurons in the anterior horn cells of the spinal cord, resulting in muscular atrophy of the limbs and torso. Depending on the age of onset of the symptoms and their clinical course, there are four different types of SMA.
The proof of concept of the efficacy of gene therapy, based on the administration of an AAV (adeno-associated virus) vector carrying the human Smn1 sequence, was provided the team of Dr Martine Barkats (Institut de Myologie – INSERM UMR 974, Paris) using a mouse model of SMA type I (Dominguez et al., Journal Hum Mol Genet 2010).
Preclinical studies are ongoing to define the strategy for a future clinical trial.