Pituitary Stalk Interruption Syndrome

**Semantic type:** Disease or Syndrome

**Definition:** A syndrome characterized by hypoplastic or aplastic anterior pituitary gland, a very thin or interrupted pituitary stalk, and ectopic or absent posterior pituitary gland, which may be associated with mutation(s) in the HESX1 or LHX4 genes.

**Synonyms:** - Hypoplastic Anterior Pituitary, Missing Stalk, and Ectopic Posterior Pituitary - PSIS