Luteinizing hormone beta-subunit gene (LHbeta) polymorphism in infertility and endometriosis-associated infertility

Objective: To establish the frequency of LHbeta G1502A polymorphism in infertile women with endometriosis, infertile women without endometriosis and a control group.

Study design: Case-control study including 110 infertile women with endometriosis, 84 infertile women without endometriosis and a control group consisting 209 healthy fertile women recruited from the ABC School of Medicine. The LHbeta G1502A polymorphism was studied by RPLP-PCR (restriction fragment length polymorphism-polymerase chain reaction).

Results: Genotypes GG, GA and AA of the LHbeta G1502A polymorphism presented frequencies of 54.6%, 31.8% and 13.6%, respectively, in the women with endometriosis (p=0.0398); of 52.4%, 38.1% and 9.5% (p=0.0123), respectively, in the infertile women without endometriosis; and of 68.9%, 21.5% and 9.6%, respectively, in the control group. In patients with minimal/mild endometriosis and moderate/severe endometriosis, the GG, GA and AA genotype frequencies were, respectively, 47.3%, 36.4% and 16.3% (p=0.0118); and 61.8%, 27.3% and 10.9% (p=0.5975). Considering the alleles, allele G was present in 70.5% of the patients with endometriosis, 71.4%% of the infertile women without endometriosis and in 79.7% of the controls, whereas allele A was present in 29.5%, 28.6% and 20.3%, respectively, in the infertile women with endometriosis (p=0.0121), infertile women without endometriosis (p=0.0409) and controls. Alleles G and A presented frequencies of 65.5% and 34.5% and 75.5% and 24.5%, respectively, in minimal/mild endometriosis (p=0.0026) and moderate/severe endometriosis (p=0.4062).

Conclusion: The data suggest that LHbeta G1502A polymorphism may be involved in the predisposition to infertility and minimal/mild endometriosis-associated infertility, although endometriosis might be only a coincidental finding along with infertility.