The Role of Mediator Complex Subunit 12 in Leiomyoma Biology

Purpose of Review Uterine Leiomyomas are one of the most common clinically relevant solid tumors occurring in women of reproductive age. Until recently not much was known about the genetic etiology of these tumors. This review focusses on some of the past and present findings which have greatly contributed to a better understanding of the genetics of uterine leiomyomas. Recent Findings Next generation sequencing has shown that MED12 exon 2 variants are recurrently mutated in about 70 % of human uterine leiomyomas, implying a role of MED12 in leiomyoma biology. We further discuss the development of Med12 exon 2 variant models validating a role of these variants in leiomyoma causation via gain of function mechanism. Summary Evidence from genomic studies and animal models strongly supports a role of MED12 in leiomyoma causation. The Med12 mouse models not only provide mechanistic insights but also provide a valuable platform to develop new treatment strategies against leiomyomas as an alternative to hysterectomy.