There are many causative genes for its isolated form or for multihormonal hypopituitarism, such as TSHβ, TRHR, TBL1X and IRS4 (for heritable isolated central hypothyroidism) and PROP1, HESX1, SOX3 (for multihormonal hypopituitarism) [5,6]. Here, PROP1 is linked to hypopituitarism.