Gene expression analysis of leprosy by using a multiplex branched DNA assay

Leprosy is caused by Mycobacterium leprae, and the global registered prevalence of leprosy at the beginning of 2009 stood at 213 036 cases. It has long been thought that leprosy has a strong genetic risk. Recently, we have identified significant associations (P < 1.00 x 10-10) between SNPs in the genes CCDC122, C13orf31, NOD2, TNFSF15, HLA-DR and RIPK2 and a trend towards an association (P = 5.10 x 10-5) with a SNP in LRRK2. Here, we investigated the expression of these seven genes in formalin-fixed, paraffin-embedded skin tissues of leprosy and matched normal tissues using branched DNA technology. This technology allows for direct measurement of targeted mRNA within cellular lysate using a 96-well plate format in a time frame compared to a reporter gene assay. The clear upregulation of all seven genes was found in leprosy tissues compared to normal tissues, which further supports our genome-wide association study results.