In this study, 20 (7.8%) of the fibroids had a chromosomal rearrangement of 12q14-15 reflecting the rearrangement of the HMGA2 allele, while 179 (69.9%) of the fibroids exhibited a mutation of mediator complex subunit 12 (MED12), a transcription factor gene17. The gene discussed is HMGA2; the disease is leiomyoma.