It has been recognized for 40 years that the variable (diversity) joining [V(D)J] recombination-mediated assembly of diverse B and T lymphocyte antigen receptor (AgR) genes is not only essential for adaptive immunity, but also a risk for autoimmunity and lymphoid malignancies.
Although, the cytotoxic T lymphocyte antigen-4 gene polymorphism at position 49 of exon-1 has been strongly elucidated in different autoimmune diseases, but its role in predisposition to systemic sclerosis (SSc) is yet controversial.
The role of regulatory polymorphisms in determining susceptibility to a number of complex disease traits is discussed, including variation at the VNTR of INS, encoding insulin, in type 1 diabetes and polymorphism of CTLA4, encoding cytotoxic T lymphocyte antigen, in autoimmune disease.