Anti-Survival Motor Neuron (SMN) Antibody

Survival Motor Neuron (SMN) protein, also known as Gemin1, is derived from the SMN gene which has two nearly identical copies located on chromosome 5q13, SMN1 and SMN2 (Lefebvre et al, 1995). SMA, Spinal Muscular Atrophy, is a neurodegenerative disease caused by mutations of the SMN gene that result in a loss of motor neurons and subsequent progressive limb and trunk muscular atrophy and paralysis (Crawford et al, 1996). SMN1 produces functional, full-length SMN protein, while SMN2 encodes a truncated form of SMN protein that is unstable and defective (Wolstencroft et al., 2005). SMN2 plays a key role in the development of SMA in that the number of SMN2 copies modulates disease severity (Monani et al, 2000). The SMN protein is expressed ubiquitously and found in the cytoplasm as well as nuclear Cajal bodies (Young et al, 2000).