STOCHASTIC DETERMINATION OF THE CHROMOSOMAL REGION RESPONSIBLE FOR EXPRESSION OF HUMAN GLIAL FIBRILLARY ACIDIC PROTEIN IN ASTROCYTIC TUMORS

Previous investigators have localized the human glial fibrillary acidi c protein (GFAP) gene in the segment 17q21 in chromosome 17. In the pr esent study, we statistically assessed the association between the all elic status in thirty-three microsatellite loci and the immunohistoche mical expression of GFAP in twenty human astrocytic tumors. The result s demonstrated that the loss of heterozygosity in only one locus (D17S 795 located in 17q21.2) was significantly associated with the impaired expression of GFAP (P = 0.0280, Pc = 0.0384 by Fisher's exact test). The adjacent loci located in 17q21.1 and 17q21.3 were not relevant to GFAP expression. Those data suggest that the critical region responsib le for GFAP expression (coding sequence and regulatory elements) is lo cated close to the locus D17S795 in the segment 17q21.2. (C) 1998 Else vier Science Ireland Ltd.