Predicting (side) effects for patients with inflammatory bowel disease: The promise of pharmacogenetics

Table 1 Pharmacogenetic associations in inflammatory bowel disease

Class of drugs	Response	Gene	Clinical utility
5-Aminosalicylates1	Nephrotoxicity	HLA-DRB1	No (low incidence, high allele frequency)
Thiopurines	Myelosuppression	TPMT NUDT15	Yes
	Alopecia	NUDT15	Yes
	Pancreatitis	HLA-DQA1-HLA-DRB1	Yes
TNF-antagonists	Immunogenicity	HLA-DQA1	Yes

¹No attempt has been made to replicate this association in an independent cohort because of the scarcity of cases. Gene refers to the genes within genetic variants that have been associated to specific drug responses. HLA: Human leukocyte antigen; TPMT: Thiopurine S-methyltransferase; NUDT15: Nudix hydrolase 15.