The coding region of GABA type B receptor subunit (GABBR)-1 is located on chromosome 6, 6p21.3, and the major histocompatibility complex (MHC) located in this region is associated with multiple sclerosis, Alzheimer’s disease, schizophrenia, narcolepsy, epilepsy, and RA (81). The gene discussed is GABBR1; the disease is rheumatoid arthritis.