KCNK9 imprinting syndrome (KIS), also known as Birk-Barel syndrome (MIM: 612292), is a rare genetic disorder caused by a genetic alteration of the maternal copy of KCNK9, first reported with the causal variant, p.(Gly236Arg) [5], and two subsequent variants of uncertain significance (VUS) [6, 7]. This evidence concerns the gene KCNK9 and Birk-Barel syndrome.