eLife assessment
This important work by Hann et al. advances our understanding of the role of the survival motor neuron (SMN) protein in coordinating pathogenesis of the spinal muscular atrophy (SMA). The authors provide convincing but, nevertheless, incomplete evidence in terms of skeletal analyses not being able to satisfactorily elucidate SMN regulation of bone development. The paper appears to be descriptive and will benefit from additional experiments to justify the hypothesis. With amendments, this work will be of broad interest to biologists especially those working on the SMA.