title: Association of molecular variants of luteinizing hormone with menstrual disorders.
abstract: 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.
  
  
  METHODS
  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.
authors.affiliation: Department of Obstetrics and Gynaecology, National University of Singapore, National University Hospital, Singapore.
authors.forename: L N
authors.initials: LN
authors.lastname: Ramanujam
authors.forename: W X
authors.initials: WX
authors.lastname: Liao
authors.forename: A C
authors.initials: AC
authors.lastname: Roy
authors.forename: A
authors.initials: A
authors.lastname: Loganath
authors.forename: H H
authors.initials: HH
authors.lastname: Goh
authors.forename: S C
authors.initials: SC
authors.lastname: Ng
mesh_terms: D000236:Adenoma / Q000150:complications; D000293:Adolescent; D000328:Adult; D000568:Amenorrhea / Q000209:etiology / Q000235:genetics; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004412:Dysmenorrhea / Q000235:genetics; D005260:Female; D006801:Humans; D007986:Luteinizing Hormone / Q000235:genetics*; D008595:Menorrhagia / Q000235:genetics; D008599:Menstruation Disturbances / Q000235:genetics*; D009839:Oligomenorrhea / Q000235:genetics; D010911:Pituitary Neoplasms / Q000150:complications; D017354:Point Mutation; D011085:Polycystic Ovary Syndrome / Q000235:genetics; D012150:Polymorphism, Restriction Fragment Length; D016649:Primary Ovarian Insufficiency / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D007986:Luteinizing Hormone