This study is supported by the National Institute of Mental Health. It seeks to better characterize the genetic structure of the major histocompatibility complex (or human leukocyte antigen, HLA) region in diverse US populations. HLA is highly polymorphic and encompasses >200 protein-coding genes involved in the immune response. Though HLA genetic influence has been indicated in multiple major psychiatric diseases (e.g., schizophrenia and major depressive disorder), how it affects the development of suicidality is still unknow. It is also essential to study the underlying immunological pathways initiated or mediated by HLA region. We will address these questions by whole genome sequencing, population genetics, and disease gene fine-mapping. 
 

As an extension, we are also funded by Brain and Behavior Research Foundation (BBRF) to study the impact of social isolation in the pathway from genetic risk to suicidality development in older adults. The triangulated mechanistic evidence (social, immunological, and genetic) will guide us to design more efficient suicide prevention strategy in future.