Which genetic factors are involved in rheumatoid arthritis?

Which genetic factors are involved in rheumatoid arthritis?

• A. HLA-DRB1 & DRw4
• B. MHC
• C. Both MHC and HLA-DRB1 & DRw4
• D. None

Answer: (C)

Genetic predisposition to rheumatoid arthritis is tightly linked to the MHC region, especially the HLA class II molecules. The HLA-DRB1 gene encodes part of the DRβ1 molecule, and certain DRB1 alleles, notably those in the DR4 serotype (historically called DRw4), carry a shared epitope that raises susceptibility and is often associated with more severe disease. Because DRB1 is within the MHC region, the genetic risk involves both the broad MHC locus and the specific HLA-DRB1/DRw4 alleles. While other non-MHC genes also contribute, these together capture the strongest genetic association seen in rheumatoid arthritis.

Genetic predisposition to rheumatoid arthritis is tightly linked to the MHC region, especially the HLA class II molecules. The HLA-DRB1 gene encodes part of the DRβ1 molecule, and certain DRB1 alleles, notably those in the DR4 serotype (historically called DRw4), carry a shared epitope that raises susceptibility and is often associated with more severe disease. Because DRB1 is within the MHC region, the genetic risk involves both the broad MHC locus and the specific HLA-DRB1/DRw4 alleles. While other non-MHC genes also contribute, these together capture the strongest genetic association seen in rheumatoid arthritis.