A t(X;1)(p11.2;q21.2) has been reported in cases of papillary renal cell tumors arising in males. In this study two cell lines derived from this tumor type have been used to indicate the breakpoint region on the X chromosome. Both cell lines have the translocation in addition to other rearrangements and one is derived from the first female case to be reported with the t(X;1)(p11.2;q21.2). Fluorescence in situ hybridization (FISH) has been used to position YACs belonging to contigs in the Xp11.2 region relative to-the breakpoint. When considered together with detailed mapping information from the Xp11.2 region the position of the breakpoint in both cell lines was suggested as follows: Xpter → Xp11.23 - OATL1- GATA1 - WAS - TFE3 - SYP - t(X;1...