Objective: To localize susceptibility loci in Chinese systemic lupus erythematosus (SLE) cohort by linkage disequilibrium mapping the genomic interval in human chromosome 16 so as to understand whether the pathogenesis of human SLE is related to chromosome 16.
Methods: Five microsatellite markers in chromosome 16 spanning from 57.79 cM to 65.1 cM were used for fluorescence based genotyping in 157 SLE families. Evidence for linkage disequilibrium was assessed using the extended transmission disequilibrium test (ETDT) program and Genehunter software. Susceptibility gene was searched in the positive locus, and real-time PCR method was used to detect gene expression.
Results: With the ETDT, evidence for linkage disequilibrium of the marker D16S409 (P=0.0278) and D16S517 (P<0.0001) with SLE were found. It was observed that 271 bp allele of D16S517 was much in evidence for preferential transmission, while 277 bp allele was found to be transmitted less often than expected. Genehunter analysis is concordant with ETDT. By real-time PCR, OAZ(OLF1/ EBF-associated zinc finger protein) gene which is located in the positive locus showed higher expression in SLE patients than in normal controls.
Conclusion: Results reveal that 16q12 (58.46 cM) is associated with Chinese SLE. OAZ is a likely susceptibility gene in this locus for SLE.