T (minor) allele is associated with significantly reduced levels of active ABCC4 protein in the body (R). This causes 6-thioguanine nucleotide to build up in cells because the ABCC4 cannot remove the molecule (R).
The T (minor) allele is associated with:
Increased sensitivity to thiopurine (anti-cancer, immuno suppressant) drugs in inflammatory bowel disease patients in remission (R). This is because 6-thioguanine nucleotide (an active ingredient of thiopurine) cannot be exported from the cell.