Microcephaly and CS are recurrent features in Arboleda−Tham syndrome, with several cases of midline synostosis and pansynostosis described in association with truncating variants in KAT6A (Tham et al., 2015; Kennedy et al., 2019; Timberlake et al., 2019; Marji et al., 2021; Korakavi et al., 2022). The gene discussed is KAT6A; the disease is Cowden syndrome 1.