SMN1 and nervous system disorder: Spinal muscular atrophy (SMA) is a devastating neurological disease affecting patients of all ages.1 Commonly affecting young infants, SMA results in motor neuron loss leading to generalized weakness and paralysis.1 The genetic basis of SMA is deletion or mutation in the ubiquitously expressed Survival motor neuron 1 (SMN1) gene,2 which encodes a protein (SMN) involved in housekeeping functions, including RNA metabolism and splicing.3