Genome, epigenome and transcriptome analyses of a pair of monozygotic twins discordant for systemic lupus erythematosus

Information to distinguish genetic and environmental factors in the pathogenesis of multifactorial diseases can be obtained by investigation of disease development in monozygotic twins. Recent reports have shown that there are genomic and epigenomic differences between monozygotic twins. Genomic/epigenomic and gene expression analyses were performed in monozygotic twins discordant for systemic lupus erythematosus (SLE) to find the genes playing important roles in SLE pathogenesis. Single nucleotide polymorphism (SNP) and copy number variation (CNV) typing, CpG methylation and gene expression were analyzed. The discordances in SNPs and CNVs were not confirmed. Both CpG methylation and gene expression levels were different for 10 genes. There were no genomic differences between monozygotic twins discordant for SLE, but epigenomic and gene expression differences were detected. These findings provide information for better understanding of SLE pathogenesis.