Authors: Anas Alamri

Abstract

Background: Epilepsy is a chronic neurological illness characterized by two unprovoked seizures occurring more than 24 hours apart, or a single seizure with a significant chance of recurrence. Carbonic anhydrase (CA) is a crucial enzyme in physiological functions.CA II deficiency is a rare autosomal recessive disorder caused by mutations in the CA2 gene, is mainly characterized by osteoporosis. Recent research highlights the complex relationship between CA II and epilepsy; while CA II deficiency may provide resistance to seizures in animal models, it can also provoke seizures by disrupting brain pH regulation. This dual effect indicates CA II's critical role in maintaining normal brain function and its potential implications for seizure development in related genetic disorders. Herein we presented a rare case of 22 years old female who had a history of epilepsy, and recently she was diagnosed with CAII inherited deficiency which caused osteoporosis and consequently, multiple bone fractures.

Case Presentation: 22-year-old female with a history of absent seizures presented to the ER after a fall resulting in bruises post-convulsion. Diagnosed with epilepsy at age 12, her seizures, lasting 2-3 minutes, involve staring without tonic-clonic activity. She experienced intellectual disability and chronic bone pain. During examination, she demonstrated confusion and had two absent seizures. Vital signs were stable, with some laboratory findings indicating hyponatremia and hypokalemia. Despite treatment with Trileptal and Keppra, seizures remained uncontrolled, leading to a diagnosis of carbonic anhydrase II deficiency causing osteopetrosis and basal ganglia calcification. The treatment plan included stopping Keppra and initiating Depakin while maintaining Trileptal dosage. Gene testing confirmed CAII deficiency.

Conclusion: Our case presents the first instance of epilepsy associated with carbonic anhydrase II (CA II) deficiency, and complicated with severe osteoporosis. CAII is an autosomal recessive disorder that impacts acid-base balance and bone resorption. This highlights the need to consider CA II deficiency in patients with osteopetrosis and cerebral calcification. Effectiveness of antiepileptic medication may be influenced by this deficiency. Further research is necessary due to the limited existing literature on this topic

Keywords: Epilepsy, Carbonic anhydrase II, Seizures, Osteoporosis.