Screening of the entire coding and major promoter regions of the CYP19 gene
identified two novel polymorphisms at codon 39 (Trp to Arg) and codon 408
(silent) in addition to those reported previously at codon 264 (Arg to Cys)
and intron 4 [tetranucleotide (TTTA) simple tandem repeat]. A case-control
study was conducted in order to see whether or not these polymorphisms wer
e associated with breast cancer risk in Japanese women. Homozygous and hete
rozygous carriers of the variant allele Arg at codon 39 showed a significan
tly decreased risk of breast cancer (OR=0.39, 95%C.I.=0.17-0.89). On the ot
her hand, homozygous carriers of the allele with 10 or more TTTA repeats at
intron 4 showed a trend toward an increase (OR=1.80, 95%C.I.=0.97-3.36) in
breast cancer risk. Other polymorphisms were found not to be associated wi
th breast cancer risk These results suggest that the CYP19 polymorphisms at
exon 39 and intron 4 would be useful for selecting Japanese women at a hig
h risk of breast cancer. (C) 2000 Wiley-Liss, Inc.