Atypical HGPS and MAD‐B patients exhibit several clinical phenotypes including stunted growth, lipodystrophy, micrognathia, and hair loss, which overlap substantially, albeit not completely, with those of Zmpste24‐deficient mice (Bergo et al., 2002; Ibrahim et al., 2013). The gene discussed is ZMPSTE24; the disease is Micrognathia.