PAC clone containing the HMGI(Y) gene spans the breakpoint of a 6p21 translocation in a uterine leiomyoma cell line.

Akin to the HMGI-C rearrangements observed in benign solid tumors with 12q14-15 abnormalities, the HMGI(Y) gene has been assumed to play a crucial role in tumors with 6p21 abnormalities. Fluorescence in situ hybridization (FISH) studies using a PAC clone containing the HMGI(Y) gene as a molecular probe have been performed on a cell line from a uterine leiomyoma with a complex translocation involving chromosomal band 6p21.3. The results revealed that the breakpoint mapped within the PAC clone as reflected by signals on the normal chromosome 6 and both derivative chromosomes 1 and 14. Thus, the breakpoint was located within the HMGI(Y) gene or its close vicinity. These findings support the idea that HMGI(Y) rearrangements are causally related to the origin of uterine leiomyomas with 6p21 abnormalities.