title: Polymorphism of methionine synthase gene in nuclear families of congenital heart disease.
abstract: OBJECTIVE
  To investigate the relation of methionine synthase (MS) gene variation with congenital heart disease (CHD) phenotype.
  
  
  METHODS
  One hundred and ninety three CHD patients (94 males and 99 females) and their biological parents (nuclear families) in Liaoning Province were selected as the case group, and another 104 normal persons (60 males and 44 females) and their parents without family history of birth defects as the control group. For all subjects the polymorphism of MS gene A2756G locus was examined by PCR-RFLP method.
  
  
  RESULTS
  In offspring of the control group the frequencies of MS genotype (+/-) and allele (+) were 10.7% and 5.3%, without existence of homozygote. The MS genotype distribution and allele frequencies of CHD patients and their mothers were not significantly different from the control (P > 0.05). The frequency of allele (+) in case fathers (5.0%) was apparently lower than that in the control (9.1%, P = 0.060), and the odds ratio (OR) was 0.53 (95% CI: 0.25-1.09). There was no difference in parents' genotype combination between the two groups, and in genotype distribution among different types of CHD. Analysis of genetic transmission indicated that mutation allele (+) existed transmission disequilibrium in CHD nuclear families. The percentage of allele (+) transmitted from parents was lower than that allele (-) with OR 0.26 (95% CI: 0.11-0.60).
  
  
  CONCLUSIONS
  MS gene variation in parents is associated with occurrence of CHD in offspring, and mutation allele (+) in parents may be related with the decrease of CHD risk in offspring.
authors.affiliation: Department of Nutrition and Food Hygiene, School of Public Health, Beijing University, Beijing 100083, China. zhuwenli@tom.com
authors.forename: Wen-Li
authors.initials: WL
authors.lastname: Zhu
authors.forename: Jun
authors.initials: J
authors.lastname: Cheng
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Dao
authors.forename: Ru-Bing
authors.initials: RB
authors.lastname: Zhao
authors.forename: Li-Ying
authors.initials: LY
authors.lastname: Yan
authors.forename: Shu-Qing
authors.initials: SQ
authors.lastname: Li
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
mesh_terms: D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004247:DNA / Q000032:analysis; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D020022:Genetic Predisposition to Disease; D006330:Heart Defects, Congenital / Q000235:genetics*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015810:Linkage Disequilibrium / Q000235:genetics; D008297:Male; D009154:Mutation; D009679:Nuclear Family; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics*
chemical_list: D004247:DNA; D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase