The effect of antiepileptic drug therapy on bone metabolism and its relatonship with the vitamin D receptor gene

Epilepsy is a paroxysmal neurological disorder of childhood. Antiepileptic drugs are known to have adverse side effects on bone metabolism. Vitamin D is a regulator of bone metabolism and its effects are derived from its relationship with the vitamin D receptor (VDR). The changes in the VDR gene expression are considered to be one of the genetic factors regulating bone metabolism. The purpose of the present study was to evaluate the changes in bone mineralization, and its relationship with vitamin D receptor gene polymorphism, in epileptic children receiving antiepileptic drug therapy, and to take early measures against any possible disorders. The study comprised 75 patients between 3 and 18 years of age, and who had received antiepileptic therapy at least for the previous two years, and 50 healthy subjects as the control group. Real-Time PCR method was used to detect vitamin D receptor BsmI polymorphism. There was no a significant difference between mean vitamin D levels of the patients and the subjects in the control group. The mean vitamin D levels did not significantly differ between the antiepileptic drug groups. There were also no significant differences between the groups, in terms of the genotypes of BsmI polymorphisms, and allele frequencies. Further studies with larger patient groups will allow us gain more insights into therapeutic interventions, and/or the contributions made by genes, for patients receiving antiepileptic therapies, and also preventative treatment for side effects. Keywords: Antiepileptic drugs, vitamin D, VDR gene polymorphism.