Involvement of the HMGI(Y) gene in a microfollicular adenoma of the thyroid

Follicular thyroid adenomas are epithelial tumors characterized by subgroup s with specific chromosomal aberrations. Here we present a case with transl ocation t(1;6)(p35;p21). In 1p35 and 6p21, two genes of the high- mobility group of proteins are located. With P1-derived Artificial Chromosome (PACs) derived from the HMG17 gene located at 1p35 and HMG1(Y) located at 6p21, f luorescence in situ hybridization was performed. The breakpoints were locat ed distal to HMG17 and proximal to HMG1(Y), but no rearrangement of the gen es was shown by FISH. However, an overexpression of the HMG1(Y) gene was de tected by RT-PCR as well as by immunohistochemistry techniques. This sugges ts a breakpoint in the proximity of the HMG1(Y) deregulating HMG1(Y) gene e xpression, a situation found in a variety of human benign mesenchymal tumor s with involvement of chromosome band 6p21. Genes Chromosomes Cancer 24:286 -289, 1999. (C) 1999 Wiley-Liss, Inc.