CTLA-4 gene polymorphism in promoter and exon-1 regions is not associated with Chinese patients with rheumatoid arthritis

Excerpt

Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) is a structural homologue of CD28, but plays a negative regulatory role in T-cell response [1, 2]. CTLA-4 has been reported to be an important negative regulator of autoimmune diseases [3]. The human CTLA-4 gene is located on chromosome 2q33 and three polymorphisms have been reported to date. The first was a dinucleotide repeat polymorphism of exon 3 [4]. At least 23 different alleles ranging from 7 to 30 AT repeats have been identified. The second polymorphism was a G to A transition at position 49 of exon 1. The single nucleotide polymorphism led to an alanine to threonine amino acid substitution of codon 17 of the leader peptide [5, 6]. The third polymorphism was identified in the promoter sequence with a C to T transition at position –318 of the promoter sequence [7]. …