Anticonvulsant Treatment Associated with Intractable Hypocalcaemia in a Female Child with Hypoparathyroidism

作者：Formosa Nancy^*; Torpiano John; Allgrove Jeremy; Dattani Mehul T

来源：Hormone Research in Paediatrics, 2015, 83(1): 62-66.

DOI：10.1159/000365048

• Hypoparathyroidism
• Hypocalcaemia
• 1-Alfacalcidol
• Anticonvulsants
• Calcium-sensing receptor

Background: We report the case of a female infant with hypoparathyroidism due to an activating mutation in the calcium-sensing receptor gene. Case Report: The child presented in the neonatal period with clinical seizures associated with severe hypocalcaemia, hyperphosphataemia, low parathyroid hormone levels and elevated urine calcium: creatinine ratios. She required intravenous calcium and phenobarbitone initially, and then oral 1-alfacalcidol (1-AC) and phenobarbitone were started. The patient had intractable hypocalcaemia in the first 5 months of life despite escalating doses of 1-AC. When the phenobarbitone was stopped at 5 months of age she was admitted soon after symptomatic hypercalcaemia. We postulate that the phenobarbitone increased the metabolism of 1-AC and thus she needed large doses of 1-AC to treat hypocalcaemia until the phenobarbitone was stopped. Her parents had no biochemical abnormalities on testing. Results: Molecular genetic analysis confirmed that our patient had a de novo missense variant, c.682G>A ( p.Glu228Lys) in exon 4 of the calcium-sensing receptor. Conclusion: This case report highlights the importance that clinicians caring for children on vitamin D and its analogues are aware of the interaction with phenobarbitone, which can result in symptomatic hypocalcaemia. 1-AC should be stored at 2-8 degrees C, otherwise it will be rendered inactive.

• 出版日期2015