KCNJ8 and Cowden syndrome 1: Mice carrying mutations analogous to CS-causing mutations in humans (Kir6.1[V65M] and SUR2[A478V]) reiterate the cardiomegaly and other vascular features of human CS (3), but we do not observe obvious GI problems, except in the more severely affected homozygous Kir6.1VM/VM or double-heterozygous SUR2WT/AV/Kir6.1WT/VM (3).