Birdshot chorioretinopathy is a bilateral, posterior uveitis that affects primarily Caucasians. Although the genetic basis of disease is not completely understood, certain factors are known, such as the strong association with human leukocyte antigen (HLA)-A29. However, given the prevalence of the HLA-A29 allele in the general population, if it were the only factor required for disease, many more people would have birdshot chorioretinopathy. It has been suggested that some environmental factor may trigger this disease entity in those who are genetically predisposed based on inheritance of the HLA-A29 allele.