MAPPING THE X-CHROMOSOME BREAKPOINT IN 2 PAPILLARY RENAL-CELL CARCINOMA CELL-LINES WITH A T(X-1)(P11.2-Q21.2) AND THE FIRST REPORT OF A FEMALE CASE

A t(X;1)(p11.2;q21.2) has been reported in cases of papillary renal ce ll tumors arising in males. In this study two cell fines derived from this tumor type have been used to indicate the breakpoint region on th e 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 hybridi zation (FISH) has been used to position YACs belonging to contigs in t he 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) - DXS255 - CLCN 5 - DXS146 - OATL2 - Xp11.22 --> Xcen. The breakpoint was determined t o lie in an uncloned region between SYP and a YAC called FTDM/1 which extends 1 Mb distal to DXS255. These results are contrary to the concl usion from previous FISH studies that the breakpoint was near the OATL 2 locus, but are consistent with, and considerably refine, the positio n that had been established by molecular analysis.