CYP2A6 Polymorphisms May Strengthen Individualized Treatment for Nicotine Dependence

Table 1

Example of CYP2A6 gene variants structures and related enzymatic activities in nicotine metabolism.

CYP2A6 gene variants	Nucleotide change	Protein alteration	Enzymatic activities
CYP2A^*1A (wild type)	None	None	Normal
CYP2A6^*1H	-745A>G	Disruption of CCAAT box	Decrease
CYP2A6^*4A	CYP2A6 deleted	No produced protein	None
CYP2A6^*9A	-1013A>G, -48T>G; 51G>A	Change in TATA box	Decrease
CYP2A6^*12A	Change Exon 3–8 of CYP2A6 origin	10 amino acid substitution	Decrease

Note: change in the nucleotide of these gene variants alters or inhibits their enzymatic activities decreasing their nicotine metabolism activities in comparison with CYP2A6^*1A (wild type) gene variants [22].