ABCC9 and hereditary gingival fibromatosis: Indeed, patients that carry mutations in other potassium channels share phenotypic similarities with our patients: a craniofacial phenotype, GHD and hypogonadotropic hypogonadism have been reported in a patient with Cantù syndrome (MIM: 239850)39, caused by gain-of-function mutations in ABCC9 or KCNJ840, gingival fibromatosis/overgrowth in patients carrying mutations in KCNJ641 and KCNH142, and a craniofacial phenotype in patients with mutations in KCNJ641, KCNJ243, and KCNK944.