P468: A case of developmental and epileptic encephalopathies without epilepsy

gland.After surgery, we gave him a hydrocortisone injection to prevent acute adrenal insufficiency.The dose of hydrocortisone was gradually reduced, and the patient was taken a low dose before discharge from our hospital.Conclusion: Genetic testing and molecular analysis, including sequencing of the VHL gene, are crucial for diagnosing VHL and identifying children at risk of additional tumors.Introduction: Von Hippel-Lindau (VHL) disease is an autosomal dominant hereditary condition that significantly increases the risk of various tumors, including pheochromocytomas, which are neuroendocrine tumors arising from the adrenal glands.In children, pheochromocytomas can sometimes be the first manifestation of VHL disease, with delayed onset of other typical manifestations, such as hemangioblastomas or retinal angiomas.VHL-related pheochromocytomas is often bilateral and can present with sustained hypertension, rather than the episodic symptoms typically seen in adults.Case Presentation: We describe the clinical characteristics, biochemical findings, genetic diagnosis and treatment outcome of a child with bilateral pheochromocytomas due to VHL.Genetic testing was performed using exome sequencing.A 14-year-old boy was found to have hypertension of 145/110 mmHg without headache, blurred vision, nausea, or vomiting.He has no edema, no hyperpigmentation, no weight loss or Cushing signs.Twenty-four-hour urinary test showed high nor-adrenaline, high dopamine, high VMA, and high HVA.Abdominal ultrasound showed a solid, heterogeneous mass with some small fluid cysts inside on both adrenal glands with the sizes of 65x52 mm and 78x67 mm, respectively.Abdominal MSCT with contrast showed both adrenal masses with the size of 64x57x57 mm and 62x59x68 mm, respectively.Exome sequencing showed a dominant heterozygous pathogenic variant of VHL gene: c. 414A>G (p.Pro138=).This variant was not detected in his parents.