Table 1.

Location and effects of CYP3A4*1B, CYP3A5*3 and UGT1A4*2 polymorphisms.

Polymorphism	Nucleotide Substitution	Reference Single Nucleotide Polymorphism (RS)	Protein Effect and Location	Functional Effect
CYP3A4*1B	−392A > G	rs2740574	Promoter region	Increased transcriptional activity, but clinical effect unclear
CYP3A5*3	698A > G	rs776746	Intron 3	Decreased or lost enzyme activity and expression
UGT1A4*2	70C > A	rs6755571	Exon 1	Decreased glucuronidation activity