Comparison of chromosomal behavior in cultured lymphocytes and fibroblasts from patients with chromosomal disorders and controls

Abstract

The occurrence of satellite association, breaks, tetraploidy or endoreduplication, and structural rearrangements was studied and compared in 600 lymphocyte and 600 skin-fibroblast metaphases from 30 karyotypically normal individuals and in 820 lymphocyte and 820 skin-fibroblast metaphases from 41 patients with various chromosomal disorders. The frequency of satellite association was less (0.02 < P < 0.05) in fibroblast than lymphocyte cultures of both the control and abnormal groups. The incidence of breaks in the controls was 2.5 % in lymphocytes and 4.2% in cultured fibroblasts. In patients with chromosomal disorders, the incidence was 5.5% in cultured lymphocytes and significantly greater (P < 0.01), 15.2%, in cultured fibroblasts. The incidence of tetraploid cells (including endoreduplication) in lymphocyte cultures was 0.2% of 3000 cells in the controls and 0.3% of 4100 cells in the abnormal group; this was significantly less (P < 0.01) than the incidence in fibroblast cultures, 3.9% of 3000 control cells and 3.7% of 4100 cells in the abnormal group. The excess of breaks and tetraploid cells in cultured fibroblasts compared to cultured lymphocytes may be due to the longer duration in culture, with increased risk of chromosomal damage, of the fibroblast cultures.