Consistent breakpoints in region 14q22-q24 in uterine leiomyoma.

The chromosomes of nine consecutive human benign leiomyomas of the uterus were studied with banding methods following short-term culture. All of the tumors had a typical benign histology. Five exhibited clonal chromosome changes including three with consistent involvement of chromosomes 12 and 14 in a translocation, t(12;14)(q14-15;q23-q24), a direct insertion, dir ins(12;14)(p11.2;q22q24.1), and a direct insertion, dir ins(14;12)(q22-q23;q14-q15q23-q24.1). Thus, this study demonstrated the presence of consistent chromosome changes in another benign proliferation. Strikingly, the breakpoint observed at 12q14-q15 in two specimens is also involved nonrandomly in other benign proliferations such as mixed salivary gland tumors and lipomas. However, region 14q22-q24, which was involved in three specimens, may contain a DNA sequence critical for the genesis of uterine leiomyoma.