**5.9 Genetics**

The risk of developing osteonecrosis is also associated with gene predisposition. Some studies have shown an association between the FDPS (farnesyl diphosphate synthase gene) which encodes a key enzyme of the mevalonate pathway and the development of osteonecrosis of the jaw. That is why are tested rs2297480, a SNP region on the FDPS gene. Studies have been conducted in patients who have suffered from multiple myeloma or metastatic carcinomas and have been treated with zoledronate acid [54].
