Last update : April 2015.
The Human Leucocyte Antigen (HLA) genes are on important component of the immune system regulation. They are cell-surface antigen-presenting proteins present in almost every cell of the body. Their role is to signal to white blood cells (more specifically T cells) that a cell has been contaminated by a pathogen (virus or bacteria) and should be destroyed. As such, HLA types can play a significant role in many autoimmune diseases.
There are many classes of HLA. The main are A, B, C, DP, DQ and DR. Everyone has two copies of each type, one inherited from each parent. Each HLA type (e.g. HLA-A1) has several subtypes (e.g. HLA A*01:01, HLA A*01:02, HLA A*01:03). Subtypes usually vary between continent or racial groups.
These comparative tables were made using the data from HLA allele frequencies database.