This study was aimed to determine the followings in adult patients with epilepsy and on chronic treatment with AEDs (1) the types and severity of bone disease, (2) the potential mechanism(s) of osteoporosis/osteopenia induced by AEDs as data on this subject are controversial and inconsistent, and (3) the status of OPG/RANKL system (as markers of bone remodeling) and its relationship to BMD and related biochemical parameters of bone disease. This evidence concerns the gene TNFRSF11B and Osteopenia.