Pituitary stalk interruption syndrome

Disease Overview

Pituitary stalk interruption syndrome (PSIS) is a congenital abnormality of the pituitary gland  characterized by the triad of a very thin or interrupted pituitary stalk, a misplaced (ectopic) or absent posterior pituitary and a small or absent anterior pituitary, with permanent growth hormone (GH) deficit.[12986][12987] Signs and symptoms in newborns include low blood sugar levels (hypoglycemia), jaundice, congenital abnormalities and small penis (micropenis) and/or testis that are not in the scrotal sac (cryptorchidism). Later in childhood, signs may include short stature, seizures, low arterial pressure (hypotension) and/or intellectual delay.[12986] Some people can also have vision problems (septooptic dysplasia) and Fanconi anemia. The cause of this condition is unknown.  Rare mutations in the HESX1, LHX4, OTX2, SOX3, and PROKR2 genes can be the cause in familial cases.[12987][12988] The diagnosis is confirmed through MRI showing the characteristic findings. Treatment is based on replacement of deficient hormones, particularly GH, and should be started at birth to avoid hormone deficiencies and intellectual delay.[12986][12988]

Synonyms

• Ectopic neurohypophysis
• PSIS