Localization of the human dihydropteridine reductase gene to band p15.3 of chromosome 4 by in situ hybridization.

We report the localization of the gene for dihydropteridine reductase (DHPR) to the human chromosome region 4p15.3 by in situ hybridization using a cDNA probe to the enzyme. The distal end of the short arm of chromosome 4 is of considerable interest because the gene responsible for Huntington's disease is located in this region. Although this part of the chromosome is being extensively studied, DHPR is the first well-characterised gene to be assigned to the region. Restriction enzyme fragment length polymorphisms have been detected with a number of restriction endonucleases, including AvaII and MspI. These features may make the DHPR cDNA clone a useful probe not only for prenatal diagnosis of DHPR deficiency but also for linkage studies of Huntington's disease.