Pituitary Stalk Interruption Syndrome – clinical Presentation and Management of a Potentially Life-threatening Disease in Newborns

Pituitary stalk interruption syndrome (PSIS) is a rare congenital disease resulting in hypopituitarism of variable degree. Serious courses, due to severe combined pituitary insufficiency, are even rarer and associated with very early manifestation immediately after birth. The first clinical signs are elusive and lead to delayed diagnosis and treatment, often resulting in life-threatening complications. The objective was to highlight early leading symptoms and key issues of PSIS in neonates to increase awareness, improve clinical management and thereby enable an early diagnosis and treatment to prevent further complications. This report presents and compares the clinical course and management of two male neonates with PSIS. Early leading symptoms were the same in both patients, including recurrent hypoglycaemia, hyponatraemia, jaundice, cholestasis, sucking weakness and genital abnormalities. Patient 1 developed an infection-induced adrenal crisis, persistent substitution-dependent thrombocytopenia and convulsions due to severe hypoglycaemia because of delayed PSIS diagnosis. In patient 2, with recognition of the leading symptoms, endocrine testing and a subsequent cerebral magnetic resonance imaging were performed early and he was diagnosed and treated before major complications occurred. Genetic testing was performed in both patients. A heterozygous variant in