The G allele of rs231775 is a risk factor for PBC, while AA genotype of rs3087243 and GG, GA and G allele of rs231725 show negative associations with PBC.
The CTLA-4 haplotype 1 (rs231775 G, rs231777 C, rs3087243 G, rs231725 A; GCGA) was a risk factor for PBC susceptibility but a protective factor for PBC progression.
One CTLA4 gene SNP (rs231725) was significantly associated with susceptibility to anti-mitochondrial antibody (AMA)-positive PBC, but clinical significance disappeared after correction for multiple testing.
We identified a novel and relatively strong association between PBC and rs231725, a SNP in the 3' flanking region of CTLA4 located outside of the area previously investigated in PBC.