POU1F1 and hypopituitarism: Hypopituitarism can have a congenital cause due to mutations in genes involved in pituitary development and endocrine cell differentiation, such as POU class 1 homeobox 1 (POU1F1, also known as PIT1) and orthodenticle homeobox 2 (OTX2) or can be acquired during life (13–16).