Restriction fragment length polymorphisms among Japanese detected with a dihydropteridine reductase cDNA gene probe.

Using a human dihydropteridine reductase (DHPR) cDNA, the frequency of restriction fragment length polymorphisms (RFLPs) with restriction endonucleases AvaII, MspI, NcoI and HinfI was estimated in unrelated, unaffected Japanese. The allele frequencies are different from those found in Caucasians, especially with MspI and HinfI. However, approximately 60% of Japanese are heterozygous for at least one of the RFLPs and analysis of one family with DHPR deficiency was shown to be informative. RFLP linkage analysis will be useful in the Japanese population as previously reported for Caucasians.