Deoxyribonuclease I gene polymorphism in Han Chinese population: frequency and effect on glucose and lipid parameters

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.

Association between gap junction protein-alpha 8 polymorphisms and age-related cataract

GJA8 plays an important role in lens growth and transparency. Therefore, we hypothesized that two single nucleotide polymorphisms (SNPs) in GJA8 might be associated with age-related cataract. We investigated the SNPs rs1495960 and rs9437983 using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing, in 96 age-related cataract patients, and 208 gender- and age-matched healthy controls. No significant differences between cases and controls were seen in genotype or allele distributions of rs1495960 (P > 0.05). The allele distribution of rs9437983 was different between cases and controls, but no difference was detected in its genotype distribution. Cataract patients had a significantly lower G-G haplotype frequency (4.9% vs. 15.5%, P = 0.0001), and a significantly higher G-A haplotype frequency (45.6% vs. 36.4%, P = 0.030) than controls. Limiting to nuclear cataract cases significantly increased the differences between cases and controls for G-G and G-A haplotypes. These results support that the GJA8 gene may be a novel susceptibility gene for age-related cataracts.