Nonrandom de novo chromosome aberrations in human lymphocytes and amniotic cells.

Abstract

The incidences and types of chromosome aberrations in single cells of individuals with a normal chromosome constitution were studied in two cell types, viz. lymphocytes and amniotic cells. A total of 17, 545 lymphocytes and 17, 262 amniotic cells were analyzed from 2, 554 consecutive individuals. The total incidence of numerical and structural aberrations was 2.0% and 1.6% in lymphocytes and amniotic cells, respectively. Two particular translocation types-t (7:14) (p 14–15; q 11–12) and t (7;14) (q 36: q 12)-were present in the lymphocytes of 1/145 individuals (1/1, 595 metaphases), whereas none of the amniotic cell metaphases displayed such a translocation. Otherwise, no apparent differences were found between the two cell types as regards incidences and types of numerical and structural aberrations. None of the structural aberrations found in lymphocytes and amniotic cells were identical to any of the consistent chromosome aberrations characteristics of malignant cells. The fact that the breakpoints in structural chromosome aberrations in isolated somatic cells seem to be basically different from these characteristic of neoplastic cells supports the conclusion that the cancer-associated aberrations are produced by mechanisms that actively favor the formation of such aberrations.