The Wallerian degeneration slow (Wlds) gene does not attenuate disease in a mouse model of spinal muscular atrophy

Spinal muscular atrophy (SMA) is a severe neuromuscular disease characterized by loss of spinal α-motor neurons, resulting in the paralysis of skeletal muscle. SMA is caused by deficiency of survival motor neuron (SMN) protein levels. Recent evidence has highlighted an axon-specific role for SMN protein, raising the possibility that axon degeneration may be an early event in SMA pathogenesis. The Wallerian degeneration slow (Wlds) gene is a spontaneous dominant mutation in mice that delays axon degeneration by approximately 2–3 weeks. We set out to examine the effect of Wlds on the phenotype of a mouse model of SMA. We found that Wlds does not alter the SMA phenotype, indicating that Wallerian degeneration does not directly contribute to the pathogenesis of SMA development.