FISH ANALYSES OF A NEWLY ESTABLISHED THYROID-TUMOR CELL-LINE SHOWING A T(1-19)(P35 OR P36.1-Q13) REVEAL THAT THE BREAK POINT LIES BETWEEN 19Q13.3-13.4 AND 19Q13.4

Translocations involving the long arm of human chromosome 19 are speci fic chromosomal alterations found in a subset of benign thyroid tumors . In the present communication we describe the establishment of an SV4 0-transformed cell line derived from a thyroid adenoma with a t(1;19)( p35 or p36.1;q13). Cytogenetic studies were carried out on this cell l ine, using a series of cosmids mapping along the long arm of chromosom e 19. In situ hybridization with probes for RYR1, ATP1A3, BCKDHA, ERCC 1, POLD1, and TRPT revealed that only TRPT mapped distal to the breakp oint of the translocation. The results indicated that the breakpoint i s located between POLD1 and TRPT at the boundary between chromosome ba nds 19q13.3 and 19q13.4.