Characterization of the survival motor neuron (SMN) promoter provides evidence for complex combinatorial regulation in undifferentiated and differentiated P19 cells.

There exist two SMN (survival motor neuron) genes in humans, the result of a 500 kb duplication in chromosome 5q13. Deletions/mutations in the SMN1 gene are responsible for childhood spinal muscular atrophy, an autosomal recessive neurodegenerative disorder. While the SMN1 and SMN2 genes are not functionally equivalent, up-regulation of the SMN2 gene represents an important therapeutic target.