Allelotype analysis of uterine leiomyoma: Localization of a potential tumor suppressor gene to a 4-cM region of chromosome 7q

Uterine leiomyoma is a benign smooth muscle tumor of the myometrium and is the most commonly encountered neoplasm in women of reproductive age. As for most benign tumors, the pathogenesis of leiomyoma remains obscure, especia lly at the molecular genetic level. The purpose of this study was to perfor m a genome-wide allelotype analysis to identify potential sites of tumor su ppressor gene inactivation. Fifty-two cases of uterine leiomyoma were subje cted to allelotype analysis by using matched pairs of tumor and blood DNA. Loss of heterozygosity (LOH) was assessed at 61 microsatellite markers dist ributed throughout the genome and representing all 41 chromosome arms. In g eneral, LOH was very rare except on chromosome 7q, where LOH was observed i n 34% of all informative tumors. Fine-deletion mapping with 25 microsatelli te markers from the 7q22 region revealed a minimal deletion unit of approxi mately 4 cM, bounded by the markers D7S2453 proximally and D7S496 distally, that probably harbors a novel tu mor suppressor gene involved in the etiol ogy of this tumor. (C) 1998 Wiley-Liss, Inc.