Objective     To study the relationship between the polymorphism of estrogen receptor α gene (ERα)and unknown aetiological hypomenorrhea in the women from Southwestern China.      Methods     Totally 100 hypomenorrhea and 100 eumenorrhea women from Southwestern China served respec

tively as case group and control group. Restriction fragment length polymorphism (RFLP) was used to analyze the first intron incision enzyme PvuⅡ and XbaⅠin ERα gene. Short tandem repeat (STR) in hypervariable region of the gene was depurated

cloned and sequenced. The distribution of the gene genotype was studied in case group and control group.      Results     P genotypic frequency was 47.5% in case group

and 30.5% in control group (

OR

1.810

95%

CI

1.113-2.765

P

=0.012). While X genotypic frequency was 20.5% in case group and 32.0% in control group (

OR

0.641

95%

CI

0.361-0.898

P

=0.036).

Pvu

Ⅱ and

Xba

Ⅰ restriction fragments were distributed in polymorphism in the 2 groups. The TA13 allele frequency was higher in case group than in control group (

P

<

0.01)

while TA15 allele frequency was lower in the former than in the later group (

P

<

0.05).      Conclusion     ERα gene polymorphism has a relation with unknown aetiological hypomenorrhea. P allele may be the risk factor

and X allele be its guard factor. TA13 allele may be the risk factor

and TA15 allele may be its guard factor.