Endocrine Abstracts

JOINT3188

Background: Recurrent hypoglycemia in infants can result from a variety of causes, complicating the diagnostic process. The episodic nature of symptoms and the need for timely metabolic and genetic testing make the workup particularly challenging. Early and accurate identification of the underlying cause is essential to prevent neurological damage and guide appropriate management.

Clinical presentation: A 2 month old female presented with a history of seizures from 17 days of life. At the age of 2 months it was noticed that her seizures were secondary to hypoglycaemia. She was born at term with a birth weight of 2. 73kg. She has no positive family history. Of note, she has 3 siblings, 1 of which demised at the age of 9 months due to unknown causes but was noted to be malnourished.

Results and discussion: Biochemistry revealed a hypoglycaemia (glucose 2. 2 mmol/l) with an inappropriately normal insulin of 5. 9m IU/l and normal c-peptide of 3. 2μg/l. Her serum growth hormone however at the time was 2. 8μg/l (reference: 0. 12-7. 79 μg/l) and she had a serum cortisol of only 118nmol/l, indicating the presence of hypocortisolism and possibly even growth hormone deficiency. Her CT Brain was normal and the Ga-68 Dotatate whole body PET/CT showed no avid disease. Genetic testing revealed a mutation in the hydroxyacyl-CoA dehydrogenase (HADH) gene, a key enzyme in fatty acid oxidation and insulin regulation. Thus, a genetic diagnosis of autosomal recessive congenital hyperinsulinism, subtype HADH was made. There is no know association in the literature with a HADH mutation presenting with a combination of hyperinsulinism and hypercortisolism or hypopituitarism. She responded however to treatment with diazoxide and oral hydrocortisone and is currently growing well without any hypoglycaemic events.

Conclusion: This case highlights the critical role of HADH in energy metabolism and the challenges of diagnosing and managing rare metabolic conditions in infancy.