45,X/46,XX mosaicism in patients with idiopathic premature ovarian failure

To determine whether low-level 45,X/46,XX mosaicism may be present in some women with premature ovarian failure (POF).

Slide preparations were made from lymphocyte cultures stimulated with phytohemagglutinin, and fluorescence in situ hybridization (FISH) was then performed using a biotin-labeled X-chromosome probe.

Cytogenetics laboratory.

Fifteen women with idiopathic POF, 20 age-matched controls, and an additional 10 older control women with normal reproductive histories.

Blood samples were collected.

The number of X chromosomes present in each cell.

In patients with POF, the percentage of cells with a single X chromosome (mean, 5.50) was significantly greater than in the controls of similar age (mean, 2.42). For control subjects, there appeared to be a linear correlation between the number of cells with a single X chromosome and age.

Some cases of POF may be attributable to low-level 45,X/46,XX mosaicism, which can be detected using FISH. In the lymphocytes from normal women, the rate of accumulation of cells with a single X chromosome was approximately 700 per 10(6) cells per year.