Twelve new genetic variants are associated with increased risk of systemic lupus erythematosus (SLE), according to 2 independent studies published online in this week's Nature Genetics. Together the studies increase our understanding of the genetic basis of SLE, but also highlight the differences in genetic risk factors for SLE between populations.
Systemic lupus erythematosus is a highly variable autoimmune disease in which a person's immune system attacks tissue in his or her own body. The disease course often cycles from relatively benign to more severe symptoms throughout a patient's life. The prevalence of SLE ranges from 7 to 71 cases per 100,000 people in European populations and from 31 to 70 cases per 100,000 individuals in Chinese populations.
Robert Graham and colleagues analyzed the genomes of approximately 2000 patients from the United States and Sweden and identified five new susceptibility loci that are associated with increased risk of SLE. Xue-Jun Zhang and colleagues analyzed 4000 SLE patients from China and discovered 9 new susceptibility loci for SLE, with 2 loci overlapping those found by Graham and colleagues.