Low Genetic Heterogeneity Of Copy Number Variations (Cnvs) In The Genes Encoding The Human Deoxyribonucleases 1-Like 3 And Ii Potentially Relevant To Autoimmunity

Deoxyribonucleases (DNases) might play a role in prevention of autoimmune conditions such as systemic lupus erythematosus through clearance of cell debris resulting from apoptosis and/ or necrosis. Previous studies have suggested that variations in the in vivo activities of DNases I-like 3(1L3) and II have an impact on autoimmune-related conditions. The genes for these DNases are known to show copy number variations (CNVs) whereby copy loss leads to a reduction of the in vivo activities of the enzymes, thereby possibly affecting the pathophysiological background of autoimmune diseases. Using a simple newly developed quantitative real-time PCR method, we investigated the distributions of the CNVs for DNASE1L3 and DNASE2 in Japanese and German populations. It was found that only 2 diploid copy numbers for all of these DNASE CNVs was distributed in both of the study populations; no copy loss or gain was evident for any of the autoimmune-related DNase genes. Therefore, it was demonstrated that these human autoimmune-related DNase genes show low genetic diversity of CNVs resulting in alterations of the in vivo levels of DNase activity.