Association of molecular variants of luteinizing hormone with menstrual disorders.

OBJECTIVE

Luteinizing hormone (LH) promotes ovulation and luteinization of the ovarian follicle, and stimulates steroidogenesis in the ovaries. It is known to be present in different molecular forms, and secretion of abnormal LH has been implicated in menstrual disorders and infertility. The purpose of this study was to determine any association of two recently described LH variants with menstrual disorders in Singapore Chinese women. One of these variants had Trp8 to Arg8 and Ile15 to Thr15 replacements in the LH beta-subunit, while the second variant possessed Ser102 substitution for Gly102.

PATIENTS

One hundred and seventy six patients with menstrual disorders and two hundred normal ovulatory women were recruited and screened for the presence of these two LH variants.

METHODS

The polymerase chain reaction (PCR) products of patients were analysed by restriction fragment length polymorphism (RFLP) and the results were compared with those of normal ovulatory women and confirmed by DNA sequencing.

RESULTS

Twenty one (11.9%) patients with menstrual disorders and twenty (10%) normal ovulatory women were found to carry the first variant, but its occurrence did not show any significant statistical difference between the patient and control groups (P = 0.679). However, the second variant was only detected in seven (4%) patients with menstrual disorders, and none of the normal ovulatory subjects (P = 0.005).

CONCLUSIONS

the study showed that the first variant was not associated with menstrual disorders, whereas the second variant might be implicated in menstrual disorders in some Singapore Chinese women.