Novel polymorphisms in the upstream region of the human dopamine D4 receptor (DRD4) gene

We found nine novel polymorphisms in the upstream region of the human dopamine D4 receptor (DRD4) gene of Japanese by direct sequencing. These polymorphisms are −809G > A, −768G > A, −616C > G, −603T > del, −602G > del, −600G > C, −376C > T, −291C > T, and −128G > T. One known polymorphism, −521C > T, was also recognized. Six of these sites were identified as restriction fragment length polymorphisms (RFLPs).