X chromosome loss and ageing

The detection of a low level 45, X cell line during routine cytogenetic analysis in an adult female can be difficult to interpret. In the absence of recent information regarding loss of the X chromosome and ageing, we undertook a prospective study. A total of 19,650 cells from 655 females aged from birth to 80 years were screened cytogenetically. The frequency of X chromosome loss ranged from 0.07% at age < 16 years to 7.3% at > 65 years of age and showed a highly significant quadratic relationship between X chromosome loss and ageing ( P <= 0.00001). We have produced a graphic representation that provides a minimum baseline age-related rate of X chromosome loss. This should assist diagnostic cytogenetics laboratories to determine the significance of 45, X cell lines detected in women of all ages. We also compared the frequency of 45, X cells in women referred with at least one spontaneous abortion with those referred for other reasons and found no significant difference. Thus, in our population, an excess of 45, X cells is not associated with pregnancy loss. Copyright (c) 2007 S. Karger AG, Basel