Clinical features of spinal muscular atrophy (SMA) type 2

Infantile spinal muscular atrophy (SMA) type 2 is sometimes called intermediate SMA to indicate the disease severity. Generally, psychomotor development is normal until the age of 6 to 8 months, with the acquisition of a stable sitting position. The early signs are muscle weakness, mostly affecting the lower limbs, generalized hypotonia and areflexia. The consequences of motor neuron degeneration are functional and orthopaedic, respiratory, nutritional, socio-professional, and psychological. The implementation of standardized care (i.e., standard of care recommendations) has improved the quality of life and survival outcome of patients. The emergence of innovative therapies, some of which are now available, should further improve the clinical evolution of this disease. © 2020 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.