title: Analysis of the C314T and A595G mutations in histamine N-methyltransferase gene in a Chinese population.
abstract: BACKGROUND
  Histamine N-methyltransferase (HNMT) plays an important role in the metabolism of histamine, a biogenic amine that has many physiologic and pathological roles in human tissues. A missense mutation C314T (Thr105Ile) in the HNMT gene has been identified to represent a common functional polymorphism in Caucasians, whereas an A595G (Ile199Val) variant has been reported in one HNMT cDNA from a Japanese subject.
  
  
  METHODS
  By using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay, the point mutations C314T and A595G within HNMT were both detected in 352 unrelated Chinese Han subjects.
  
  
  RESULTS
  None of the 352 subjects contained the A595G mutation, whereas 40 (11.6%) heterozygotes and 1 (0.3%) homozygote for the variant T314 allele were detected. The frequency of the variant T314 allele in this Chinese population was 0.060 (95% CI: 0.042-0.078), not different from Japanese but significantly lower than American Caucasians.
  
  
  CONCLUSIONS
  The C314T mutation represents a common functional genetic polymorphism in the Chinese Han population with a variant T314 allele frequency similar to Japanese but lower than American Caucasians, whereas the A595G mutation does not appear to exist in this population.
authors.affiliation: Pharmacogenetics Research Institute, Institute of Clinical Pharmacology, Central South University, Changsha, Hunan 410078, People's Republic of China.
authors.forename: Guo-Lin
authors.initials: GL
authors.lastname: Chen
authors.forename: Zhen-Hua
authors.initials: ZH
authors.lastname: Xu
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Guang-Ping
authors.initials: GP
authors.lastname: Wang
authors.forename: Gan
authors.initials: G
authors.lastname: Zhou
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.forename: Hong-Hao
authors.initials: HH
authors.lastname: Zhou
mesh_terms: D000328:Adult; D000483:Alleles; D019943:Amino Acid Substitution; D044466:Asian People; D004247:DNA / Q000097:blood; D017931:DNA Primers / Q000235:genetics; D005260:Female; D005838:Genotype; D006637:Histamine N-Methyltransferase / Q000097:blood / Q000235:genetics*; D006801:Humans; D008297:Male; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D017931:DNA Primers; D004247:DNA; D006637:Histamine N-Methyltransferase