Mutations of MED12 were found in uterine leiomyomas with normal karyotype, deletions or rearrangements of the long arm of chromosome 7 as sole anomaly or 6p21~23 abnormalities leading to HMGA1 rearrangement/overexpression, and it was concluded that the MED12 mutations had preceded the chromosomal aberrations [45]. The gene discussed is MED12; the disease is uterine corpus leiomyoma.