amenorrhea 6 human 6 DNA polymorphism 4 Inhibin levels 4 Inhibin α-subunit gene 4 Premature ovarian failure 4 adult 4 allele 4 alpha chain 4 article 4 confidence interval 4 controlled study 4 cytosine 4 female 4 follicular phase 4 follitropin 4 genotype 4 heterozygosity 4 inhibin 4 inhibin A 4 inhibin B 4 major clinical study 4 negative feedback 4 nucleic acid base substitution 4 premature ovarian failure 4 risk assessment 4 statistical analysis 4 thymine 4 1 [n,o bis(5 isoquinolinesulfonyl) n methyltyrosyl] 4 phenylpiperazine 2 2 (2 amino 3 methoxyphenyl)chromone 2