Distribution patterns of satellite associations in human lymphocytes relative to age and sex.

Using ammoniacal silver for differential staining of satellites, associations from 1,668 human metaphases were studied from lymphocyte cultures of 167 normal individuals and were correlated with age and sex. There is a peak in satellite association frequency up to age 20 years in males and to 25 in females. With older ages there is a decline in association frequencies. No associations with four or more chromosomes were found in newborns. Furthermore, association in newborns, as well as in individuals older than 50 years, are significantly low compared to in-between age groups. Females have a higher frequency of satellite associations than males between the ages of 3 and 50 years. Typically, females have greater multiple associations, while males have more single associations. Randomness or non-randomness of occurrence of associations fluctuates for different age groups within and between the two sexes.