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A Method to Study the C924T Polymorphism of the Thromboxane A2 Receptor Gene
Published on: April 1, 2019
The association between CYP 2C9 polymorphism and bone health
Kanitpong Phabphal1, Alan Geater, Kitti Limapichat
1Neurology Unit, Department of Internal Medicine, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand.
Seizure
|July 16, 2013
Summary
Cytochrome P450 2C9 (CYP 2C9) polymorphism is linked to higher bone mineral density (BMD) in epilepsy patients, irrespective of phenytoin levels. This finding offers new insights into epilepsy drug metabolism and bone health.
Area of Science:
- Pharmacogenomics
- Epilepsy Research
- Bone Metabolism
Background:
- Cytochrome P450 (CYP P450) enzyme-inducing anti-epileptic drugs (AEDs) are suspected to cause bone loss in epilepsy patients.
- The specific role of CYP 2C9 polymorphism in bone mineral density (BMD), vitamin D, and parathyroid hormone levels in epilepsy remains understudied.
Purpose of the Study:
- To investigate the association between CYP 2C9 polymorphism and BMD in patients with epilepsy.
- To explore the relationship between CYP 2C9 polymorphism, vitamin D levels, and parathyroid hormone levels in this patient group.
Main Methods:
- Examined 93 epilepsy patients on phenytoin monotherapy for CYP 2C9 polymorphism.
- Measured BMD of the lumbar spine and femur using dual-energy X-ray absorptiometry.
- Assessed vitamin D and parathyroid hormone levels, along with basic chemistry and phenytoin plasma levels.
Main Results:
- Approximately 18.3% of epilepsy patients carried the CYP2C9*3 variant.
- CYP 2C9 polymorphism was associated with higher femoral neck T-scores and Z-scores (p=0.02 and 0.04).
- Patients with CYP 2C9 polymorphism showed significantly lower 25-hydroxyvitamin D levels (p=0.03) and higher phenytoin plasma levels (p=0.01) compared to wild-type individuals.
Conclusions:
- CYP 2C9 polymorphism is associated with increased bone mineral density, particularly at the femoral neck.
- This association appears independent of plasma phenytoin levels.
- Findings suggest a complex interplay between CYP 2C9 genetics, drug metabolism, and bone health in epilepsy patients.
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