SAT-026 Septo-Optic Dysplasia with Preserved Pituitary Function: A Case Study

Abstract Disclosure: M. Kashat: None. L. De Mattei: None. D. Shelden: None. Introduction: Septo-optic dysplasia (SOD) is a rare, congenital brain disorder characterized by a triad of optic nerve hypoplasia, midline brain malformation, and hypothalamic-pituitary axis (HPA) dysfunction, including central diabetes insipidus (CDI). This report describes a patient with CDI, optic nerve hypoplasia, attention-deficit/hyperactivity disorder (ADHD), and other neurological manifestations secondary to SOD in the absence of clinical manifestations of panhypopituitarism. Clinical Case: A 20-year-old female with a history of SOD with CDI presented with polyuria and polydipsia. She was diagnosed with SOD at the age of 2 months due to maternal cytomegalovirus (CMV) transmission. She was previously on Synthroid, hydrocortisone, and growth hormone injections for presumed hypopituitarism. She is only on desmopressin nasal spray. She has regular menses with no symptoms of adrenal insufficiency or hypothyroidism. Water deprivation test showed a copeptin proAVP <2.8, UNa: 37, serum Osm: 314, urine Osm: 149, Na: 150, and Cl:118 consistent with CDI. Thyroid function demonstrated a TSH of 1.47 and free T4 of 0.9 without therapy. FSH, LH, ACTH, and IGF-1 are pending with no hypoglycemia and electrolyte abnormalities. Brain MRI showed an absent septum pellucidum and posterior pituitary bright spot with normal pituitary gland. She was initiated on subcutaneous desmopressin per preference. It is atypical to appreciate a normal pituitary gland in SOD on imaging. Conclusion: Dysfunction of HPA is a classic finding of SOD. Panhypopituitarism is seen in 62% to 80% of SOD cases that can be seen before the age of 2 with optic nerve hypoplasia, absent septic pellucidum and corpus callosum, and hypoplastic or absent pituitary stalk. Growth hormone deficiency, central hypothyroidism, and secondary and tertiary adrenal insufficiencies are common pituitary dysfunctions associated with the condition. Severe cases of panhypopituitarism present with hypoglycemia, genital anomalies, and failure to thrive. In the rarest cases, CDI is observed. Experts recommend screening HPA dysfunction every 4 to 6 months within the first 2 years of life, and every 6 to 12 months between 2 to 8 years, and yearly throughout puberty. There are no formal guidelines on HPA evaluation in SOD after puberty. This case exhibits a variation of SOD which features optic nerve hypoplasia, absent septum pellucidum, and CDI with clinically intact HPA and a normal pituitary gland on imaging. Presentation: Saturday, July 12, 2025