A NEW HIGH-FREQUENCY POLYMORPHISM IN THE HER-2 NEU ONCOGENE IN NORMALTISSUE AND BREAST-TUMORS/

The HER-2/neu (erbB-2) oncogene, if amplified and/or overexpressed in breast and ovarian cancers, is associated with a poor prognosis. Emplo ying direct DNA sequencing, we have discovered and sequenced an 80 bas e pair intron from human placenta which contains an A to G polymorphis m. This polymorphism lends itself to restriction fragment length polym orphism analysis of the PCR product spanning this intron. All three ge notypes, homozygous A, heterozygous, and homozygous G appear in normal control populations and breast tumors. Also, no difference was seen b etween the polymorphic form found in five breast cancers and the corre sponding normal tissue.