The significance of the number of CGG repeats and autoantibodies in premature ovarian failure

The objective of this study was to determine whether there was a threshold for the number of CGG repeats in the FMR1 (fragile X) gene in premature ovarian ageing and premature ovarian failure and to investigate the association of this sequence with serum concentrations of anti-Müllerian hormone (AMH), inhibin B, anti-thyroid and anti-adrenal autoantibodies. In this prospective randomized controlled preliminary study, the number of triple CGG repeats and serum concentrations of FSH, AMH and aforementioned autoantibodies were evaluated in 79 women who were younger than 40 years old. FSH concentrations were between 12 and 50 IU/ml (premature ovarian ageing) in 30 women and were higher than 50 IU/ml (premature ovarian failure) in nine women; FSH concentrations were normal in 40 women. All women whose FSH concentrations were higher than 12 IU/ml had CGG repeats greater than 30. No women whose FSH concentrations were normal had a repeat number above 30. There was no significant relationship between the levels of antibodies and either CGG repeat numbers or FSH concentrations. In conclusion, the number of CGG repeats between 30 and 40 might be used to predict premature ovarian ageing and premature ovarian failure in infertile women.