Anti-Mullerian hormone indicates early ovarian decline in fragile X mental retardation (FMR1) premutation carriers:: a preliminary study

BACKGROUND: Women who carry the fragile X mental retardation (FMR1) premutation are at risk for fragile X-associated primary ovarian insufficiency. Past studies have shown that carriers who are still cycling have increased levels FSH compared with non-carriers. As anti-Mullerian hormone (AMH) has been shown as an excellent marker of ovarian decline, we examined AMH levels among premutation carriers to characterize their ovarian function. METHODS: We determined the level of FSH and AMH in serum samples collected during early follicular phase from women who carried longer FMR1 repeat alleles (defined as >= 70 repeats, n = 40) and those with shorter repeat alleles (< 70 repeats, n = 75), identified by DNA analysis. Comparisons were made stratified by age and carrier status. RESULTS: For all age groups, AMH levels were significantly lower among longer repeat allele carriers compared to shorter repeat allele carriers (P = 0.002, 0.006 and 0.020 for women ages 18-30, 31-40 and 41-50 years, respectively). In contrast, increased FSH indicative of early ovarian decline was only evident for longer repeat allele carriers aged 31-40 years (P = 0.089, 0.001 and 0.261 for women ages 18-30, 31-40 and 41-50 years, respectively). CONCLUSIONS: These preliminary data suggest that AMH levels indicate early ovarian decline among women with longer FMR1 repeat alleles; moreover, AMH appears to be a better marker than FSH in identifying this early decline.