title: Thymidylate synthase enhancer region: Novel allele in Indians.
abstract: BACKGROUND
  Thymidylate synthase (TS) is the major target for fluoropyrimidine drugs like 5-Fluorouracil (5-FU). There are polymorphic tandem repeats in the TYMS gene enhancer region (TSER). The number of tandem repeats varies in different populations. The aim of this study was to determine the frequencies of the TSER tandem repeats (rs34743033) and compare the observed frequencies with those of other populations.
  
  
  METHODS
  This study genotyped 350 healthy individuals by Polymerase Chain Reaction (PCR).
  
  
  RESULTS
  A novel allele *1 (only a single repeat) was observed in four individuals, the individuals were heterozygous (TSER*1/*2) for TYMS. Another variant rs2853542 affecting the expression of Thymidylate synthase was also analysed. The observed genotype frequencies were compared with frequencies observed in other populations for understanding differences between various population groups. There was a statistically significant difference between Indians and Chinese, Kenyans, Ghanians, African-Americans, Americans of European Ancestry, British, Hungarians, Turkish, Australians and Brazilians.
  
  
  CONCLUSIONS
  This study identified a novel single repeat in the TYMS gene which might have an impact on the expression of this gene, which needs to be confirmed by functional studies.
authors.affiliation: a Department of Cellular and Molecular Biology , B. V. Patel PERD Centre , Ahmedabad , India.
authors.forename: Dipali
authors.initials: D
authors.lastname: Dhawan
authors.affiliation: a Department of Cellular and Molecular Biology , B. V. Patel PERD Centre , Ahmedabad , India.
authors.forename: Harish
authors.initials: H
authors.lastname: Padh
mesh_terms: D000328:Adult; D000483:Alleles; D001483:Base Sequence; D004587:Electrophoresis, Agar Gel; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D013940:Thymidylate Synthase / Q000235:genetics*; D055815:Young Adult
chemical_list: D013940:Thymidylate Synthase
keywords: 5-Fluorouracil; ethnic variation; tandem repeats