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 L H variants with menstrual disorders in Singapore Chinese women. One of thes e variants had Trp(8) to Arg(8) and Ile(15) to Thr(15) replacements in the LH beta-subunit, while the second variant possessed Ser(102) substitution f or Gly(102). PATIENTS One hundred and seventy six patients with menstrual disorders and two hundred normal ovulatory women were recruited and screened for the pres ence of these two LH variants, METHODS The polymerase chain reaction (PCR) products of patients were analy sed by restriction fragment length polymorphism (RFLP) and the results were compared with those of normal ovulatory women and confirmed by DNA sequenc ing, RESULTS Twenty one (11.9%) patients with menstrual disorders and twenty (10 %) normal ovulatory women were found to carry the first variant, but its oc currence did not show any significant statistical difference between the pa tient and control groups (P=0.679). However, the second variant was only de tected in seven (4%) patients with menstrual disorders, and none of the nor mal 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 men strual disorders in some Singapore Chinese women.