Aneuploidy in human lymphocytes: an extensive study of eight individuals of various ages.

Data on aneuploidy from a prospective study on a large number of lymphocyte metaphases (over 1000 in 72-h and 100 in 48-h cultures) per individual from eight healthy donors of various ages are reported. Chromosome losses were dependent on culture time, being significantly more frequent in 72-h than in 48-h cultures. All donors exhibited various degrees of aneuploidy which increased with age in women. This increase resulted essentially from X chromosome losses, as previously reported. Although the rate of aneuploidy limited to autosomes was similar in newborns and in adults, the distributions of the missing autosomes were different. In the two newborns studied, autosome aneuploidy was random. In the adults, a significant inverse correlation with autosome lengths was observed. The inverse correlation between chromosome lengths and losses may be explained by selective pressure against monosomic cells in the adults.