FGFR2 and Pfeiffer syndrome: Heterozygous activating non-mosaic germline variants in FGFR2 have been linked to numerous autosomal dominantly inherited disorders including several craniosynostoses and skeletal dysplasia syndromes such as Apert syndrome (MIM 101200), Crouzon syndrome (MIM 123500), Jackson–Weiss syndrome (MIM 123150), and Pfeiffer syndrome (MIM 101600).