Global analysis of genetic variations in a 56-bp variable number of tandem repeat polymorphisms within the human deoxyribonuclease I gene.

A 56-bp variable number of tandem repeat polymorphism is confirmed in intron 4 of the human deoxyribonuclease I (DNase I) gene (HumDN1). The purpose of the present study was to document global ethnic variations of allelic frequencies in HumDN1 VNTR polymorphisms. In this study, HumDN1 VNTR polymorphisms in 11 worldwide populations were examined by polymerase chain reaction and compared with those reported previously. Fifteen genotypes were identified in these 11 populations. Novel genotypes were found: 1/2 was observed in Ghanaians and mestizos, 3/6 was in Tamangs, 4/6 was in Tibetans and Nahuas, 6/6 was in Sinhalese. The African population showed the highest frequency for the HumDN1(∗)3 allele. Among Asian populations, the different genotype distribution was observed. The predominant allele in Mongolian, Korean, Japanese, and Chinese populations was HumDN1(∗)3, followed by HumDN1(∗)4, and then HumDN1(∗)5. In Chinese from South China, Tamangs, and Sinhalese, HumDN1(∗)4 and HumDN1(∗)5 were predominant. The allele frequency for HumDN1(∗)4 was high in three Mexican populations, but a significant difference was observed between Nahuas and Huicoles. Germans and Turks showed a similar distribution. This study is the first to show the existence of a certain genetic heterogeneity in the worldwide distribution of HumDN1 VNTR polymorphism.