Distribution and haplotype analysis of all the non-synonymous and autoimmunity-related single nucleotide polymorphisms in the human deoxyribonuclease II gene using worldwide populations.

We have focused on the 14 SNPs including all the non-synonymous and autoimmunity-related ones in the DNase II gene (DNASE2). The distribution of each allele and haplotype in these SNPs was examined in eight Asian, three African, three Mexican and two Caucasian populations using the newly developed PCR-RFLP methods. Eight SNPs among nine non-synonymous ones were monomorphic, indicating that a specific allele generating the intact activity-harboring DNase II in these SNPs is well conserved in worldwide populations. On the other hand, five other SNPs (-1951G>A, -1066G>C, -390A>C, +2630T>C, and +6235G>C) related to autoimmunity exhibited polymorphism common in worldwide populations, and especially their distributions were ethnic-dependent in the same manner as those of haplotypes. Furthermore, a strong linkage between SNPs -1951G>A and -1066G>C was confirmed in most populations. This study was the first to report any worldwide population analysis regarding all the non-synonymous and autoimmunity-related SNPs in the DNASE2, providing genetic information on the DNASE2 as a genetic marker for personal identification and/or genetic factor for susceptibility to autoimmunity.

Genetic and expression analysis of SNPs in the human deoxyribonuclease II: SNPs in the promoter region reduce its in vivo activity through decreased promoter activity.

Five SNPs in the human DNase II gene have been reported to be associated with rheumatoid arthritis (RA). Genotype and haplotype analysis of 14 SNPs, nine SNPs of which reported in the NCBI dbSNP database in addition to these five SNPs, was performed in healthy subjects. The enzymatic activities of the amino acid substituted DNase II corresponding to each SNP and serum DNase II in healthy Japanese, and promoter activities derived from each haplotype of the RA-related SNPs were measured. Significant correlations between genotype in each RA-related SNP and enzymatic activity levels were found; alleles associated with RA exhibited a reduction in serum DNase II activity. Furthermore, the promoter activities of each reporter construct corresponding to predominant haplotypes in three SNPs in the promoter region of the gene exhibited significant correlation with levels of serum DNase II activity. These findings indicate these three SNPs could alter the promoter activity of DNASE2, leading to a decline in DNase II activity in the serum through gene expression. Since the three SNPs in the promoter region of the DNase II gene could affect in vivo DNase II activity through reduction of the promoter activity, it is feasible to identify these SNPs susceptible to RA.

Confirmation that SNPs in the high mobility group-A2 gene (HMGA2) are associated with adult height in the Japanese population; wide-ranging population survey of height-related SNPs in HMGA2.

Adult height is a highly heritable trait in that multiple genes are involved. Recent genome-wide association studies have identified a novel single-nucleotide polymorphism (SNP) rs1042725 in the high mobility group-A2 gene (HMGA2) and shown it to be associated with human height in Caucasian populations. We performed a replication study to examine the associations between SNPs in HMGA2 and adult height in the Japanese population based on autopsy cases. Although we could not confirm a significant association between rs1042725 in HMGA2 and adult height, another SNP, rs7968902, in the gene achieved significance for its association in the same populations, and the effect was the same as that documented previously. These findings permit us to conclude that the SNPs in HMGA2 are common variants influencing human height across different populations. Moreover, a worldwide population study of these SNPs using 14 different populations including Asians, Africans and Caucasians demonstrated that both haplotypes and genotypes for three height-related SNPs (rs1042725, rs7968682 and rs7968902) in HMGA2 were distributed in an ethnicity-dependent manner. This information will be useful for clarifying the genetic basis of human height.