SAT139 Non-insulinoma Pancreatogenous Hypoglycemia Syndrome In A Patient With 1p36 Deletion Syndrome

Disclosure: E.D. Auckley: None. M.A. Arosemena: None. L. Philipson: None. Background: 1p36 deletion syndrome comprises a phenotypic presentation that includes central nervous system, cardiac, and craniofacial anomalies. There has been no report of associated hypoglycemia with this syndrome. Nesidioblastosis, also known as non-insulinoma pancreatogenous hypoglycemia syndrome (NIPHS), is understood as a rare condition defined by diffuse pancreatic hypertrophy with subsequent hyperinsulinemic hypoglycemia. Diagnosis requires serologic workup consistent with endogenous hyperinsulinemic hypoglycemia, intraarterial calcium stimulation positive for inappropriately elevated insulin secretion, and imaging studies without identified masses. Clinical Case: A 21-year-old female with 1p36 deletion syndrome (seizure disorder, cerebral palsy, vision loss and heart failure) was admitted to the hospital due to persistent falls. On admission vital signs were within normal limits, and physical exam revealed a thin non-verbal patient without significant other findings. During hospitalization and prolonged fasting periods of approximately 14-18 hours related to poor appetite she developed several episodes of hypoglycemia with serum glucose as low as 57 mg/dl. As patient was non-verbal at baseline, symptoms of hypoglycemia such as sweating, lightheadedness or shakiness were not confirmed. Even when she started to eat, hypoglycemic events continued to occur. Dextrose containing fluids (Dextrose 5% and later 10%) were added to try to maintain blood sugars within the normal range. Nevertheless, she continued to develop hypoglycemia. Endocrinology service was consulted and recommended to obtain a critical sample. A critical sample revealed serum glucose of 59 mg/dl, insulin level of 20.6 mcU/mL, proinsulin of 33 pmol/L, and beta-hydroxybutyrate of <0.10 mmol/L. Insulin antibodies was negative. Adrenal insufficiency was unlikely due to a normal 9 am cortisol level of 13.7 ug/dl. Due to the presence of hyperinsulinemic hypoglycemia further workup was conducted. A CT of the abdomen with a pancreatic protocol and 68Ga-DOTATATE PET/CT scan was negative for a pancreatic mass. Endoscopic ultrasound did not reveal a clear pancreatic mass either. This was followed by a calcium stimulation test which showed a two-fold increase in insulin levels in all 3 catheterized pancreatic territories. In the absence of a discrete mass, non-surgical management was recommended. For hypoglycemia management patient was started on octreotide injections with resolution of hypoglycemia. Prior to discharge she was switched to lanreotide and was discharged to continue monthly lanreotide injections. Conclusion: To our knowledge, this is the first case reported of NIPHS in a patient with a mutation in 1p36 deletion. Hyperinsulinism in the setting of diabetes has been reported in this syndrome(1) but to our knowledge no cases of hypoglycemia with NIPHS have been reported. Presentation: Saturday, June 17, 2023