HYBRIDIZATION OF CHROMOSOME-18 ALPHA-SATELLITE DNA-PROBE TO CHROMOSOME-22

Fluorescence in situ hybridization (FISH) of uncultured chorionic vill us diploid cells with a chromosome 18 alpha-satellite DNA probe (D18Z1 ) revealed a third small signal in addition to two large signals. FISH analysis of diploid metaphase cells from cultured chorionic villus ce lls and from maternal lymphocytes revealed that the third signal resul ted from hybridization to the centromere of chromosome 22. This is the first report of a variant involving D18Z1 detected by FISH and of hyb ridization of alpha-satellite from a sub-metacentric chromosome to the centromere of an acrocentric chromosome. We propose that this inherit ed variant resulted from insertion of chromosome 18 specific alpha-sat ellite DNA sequences into the centromeric region of chromosome 22. (C) 1998 John Wiley & Sons, Ltd.