Fitzgerald (1975) observed X chromosome aneuploidy in cultured lymphocytes of aging women.
Fitzgerald et al. (1975) studied a family in which 2 sisters had an unusually high frequency of this finding (in 10% of cells). Cell ... Fitzgerald (1975) observed X chromosome aneuploidy in cultured lymphocytes of aging women. Fitzgerald et al. (1975) studied a family in which 2 sisters had an unusually high frequency of this finding (in 10% of cells). Cell culture studies showed that the finding resulted from premature centromere division (PCD) restricted to the X chromosome. In the same family, 2 other sibs, a sister and a brother, had normal karyotypes, whereas 3, 2 sisters and a brother, had 1-3% of cells with PCD of the X chromosome. All 6 examined children of 1 sister with 10% PCD had normal karyotypes. Fitzgerald et al. (1975) concluded that PCD increases in frequency with age, being 4 times more frequent in women 60 years and older than in women under 40. This phenomenon was thought to be responsible for the well-documented increase in 45,X cells in older women, which is an acquired somatic mosaicism. PCD was found to be rare in men, but an age effect was suggested. Miller (1984) suggested that Fitzgerald et al. (1975) were not justified in distinguishing between individuals with 10% and 1-3% affected cells. Galloway and Buckton (1978) performed chromosome analysis on cells from 65 males and 102 females of all ages from a random sample of the population. The frequency of aneuploid cells showed a significant increase with age in both sexes, but was more marked in females and involved a high proportion of cells that had lost or gained an X chromosome, 45,X cells being much more common than 47,XXX cells. In females, the occurrence of a fragment of an X chromosome also correlated with increasing age, and the fragment appeared to be an X chromosome that had divided prematurely at the centromere.