Evidence for a Hypothalamic Defect in Septo-optic Dysplasia

A 21-year-old man demonstrated septo-optic dysplasia. Optic and retinal colobomas were present and panhypopituitarism was documented. Releasing hormone studies showed partial luteinizing hormone (LH) response and no follicle-stimulating hormone response to administration of gonadorelin (LH-releasing hormone); thyroid-stimulating hormone (TSH) and prolactin levels were increased normally after administration of protirelin (thyrotropin-releasing hormone). The LH, TSH, and prolactin responses are believed to be evidence of intact pituitary function and suggest that a hypothalamic defect accounts for the hypopituitarism.