Frequencies of the LILRA3 6.7-kb deletion are highly differentiated among Han Chinese subpopulations, and involved in ankylosing spondylitis predisposition

Leukocyte immunoglobulin-like receptor A3 (LILRA3) belongs to the multigene LILR family with unique feature of a presence or absence of 6.7-kb variation among individuals. The frequencies of the 6.7-kb deletion vary widely across populations, but so far it has not been carefully investigated among Han Chinese subpopulations. Furthermore, we previously identified the non-deleted (functional) LILRA3 as a novel genetic risk for multiple autoimmune diseases. We undertook current study to investigate i) the frequencies of 6.7-kb deletion among Han Chinese subpopulations. ii) whether the functional LILRA3 is a novel susceptibility factor for ankylosing spondylitis (AS), and iii) whether LILRA3 influences the disease activity in AS.