S. Marsh et al., Ethnic variation in the thymidylate synthase enhancer region polymorphism among Caucasian and Asian populations, GENOMICS, 58(3), 1999, pp. 310-312
Thymidylate synthase (TS) regulates the production of DNA synthesis precurs
ors and is an important target of cancer chemotherapy. A tandem repeat sequ
ence in a TS promoter enhancer region (TSER) was recently identified. Polym
orphic variation affected in vitro expression levels of the gene. We evalua
ted the influence of ethnicity on TSER genotype. Allele frequency was simil
ar in Caucasian and Southwest Asian subjects. However, homozygous triple re
peat subjects were tn-ice as common in Chinese subjects (67%) than in Cauca
sian subjects (38%). This demonstrates significant ethnic variation in a TS
gene regulatory element which may have significant impact on pyrimidine ho
meostasis and drug therapy. (C) 1999 Academic Press.