Chromosomes in old age: a six year longitudinal study.

This first longitudinal study on aged subjects confirms previous cross-sectional observations of increasing aneuploidy with advancing age in women but not in men. In this study of 17 aged twins (mean age 89.7 years), 11 women and 6 men, spanning an interval of approximately 6 years between examinations, only women showed a significant increase in hypodiploidy (also hyperdiploidy and monosomy C). This increase in hypodiploidy was not due to a high frequency of chromosome loss in a few subjects but rather was exhibited by most of the subjects. While men showed a loss in G-group chromosomes during this 6-year interval, that loss was not statistically significant. These findings confirm for the first time by means of longitudinal follow-up that women and not men, even in the ninth decade of life, show a significant increase in hypodiploidy.