HLA complex group 9 (non-protein coding) (HCG9)

HLA complex group 9 (HCG9) is a member of the PERB11 gene family located in the major histocompatibility complex (MHC) region on chromosome 6p21.33.[1] Unlike classical HLA genes, HCG9 is a non-protein-coding RNA gene and does not encode a classical receptor, enzyme, or transporter. It can exist in several splice variants but is primarily of interest due to epigenetic (especially DNA methylation) variation associated with psychiatric conditions, such as bipolar disorder. Some epigenetic studies suggest that differences in DNA methylation of HCG9 in brain, blood, and germline samples may relate to the pathogenesis of major psychosis and other psychiatric diseases.[1] It is not a direct therapeutic or diagnostic target and does not code for a protein product. Summary logic: HLA complex group 9 is not a classical therapeutic target like a receptor or enzyme; rather, it is a non-coding locus best known for epigenetic variation. Care should be taken not to confuse it with protein-coding classical HLA molecules (e.g., HLA-A, HLA-B, HLA-C), which are critical immune system targets.[1]

Other names

PERB11HCGIXHCGIX-4HCGIX4HLA complex group 9 (non-protein coding)HCG9