Aneuploidy in cultured human lymphocytes: I. Age and sex differences.

The chromosomes of the lymphocytes of 208 subjects have been analysed in order to determine the relationship between age, sex and aneuploidy. The subjects consisted of 111 females and 34 males all over 65 years and 31 females and 32 males aged between 18 and 32 years. The degree of hypodiploidy (chromosome loss) differs significantly between the elderly and young subjects of each sex and between the aged males and females. Hyperdiploidy differs significantly only between the old and the young females. Giemsa banding shows that, in elderly females, increased hypodiploidy is especially due to the loss of an X-chromosome. The possible mechanisms accounting for these results are discussed.