To assess postnatal bone growth defects observed in SMA patients and mouse models, we conducted micro-computed tomography (micro-CT) analysis on femurs obtained from postnatal day 14 (P14) SMN2 1-copy Smn1ΔMPC and SMN2 2-copy Smn1ΔMPC mice (Figure 1A). The gene discussed is SMN2; the disease is proximal spinal muscular atrophy.