Table 1.

Aetiology of gonadotropin deficiency

Acquired Causes
Neoplastic • Pituitary Adenoma • Craniopharyngioma • Meningioma • Germinoma • Rathke’s Cleft cyst	Vascular disorders • Pituitary apoplexy • Subarachnoid Haemorrhage • Sheehan’s Syndrome
Iatrogenic • Transsphenoidal surgery • Radiotherapy– brain tumour, pituitary tumour, head/ neck cancer	Hypophysis • Lymphocytic • Granulomatous: Sarcoidosis, tuberculosis, ANCA vasculitis • IgG4 • Xanthomatous
Medications • Opiates • Glucocorticoids • Immunotherapy: PD-1 & CTLA-4 inhibitors • Gonadotropin hormone releasing hormone (GnRH) analogues • Anabolic Steroids	Infiltrative • Langherans Cell Histiocytosis • Haemochromatosis • Sarcoidosis
Other
• Hyperprolactinaemia	• Empty Sella
• Traumatic Brain Injury
Congenital Causes
Kallmann Syndrome • ANOS-1, FGF-8, CDH7, SOX1, KISSR
Idiopathic congenital hypogonadotropic hypogonadism