Table III.

Genetic variation in selected glutathione-S-transferases (GSTs)

Gene	Allelea	Amino acid change	Enzyme activity	References
GSTA1	*A	Reference	Reference	27
	*B	Pt mutation, promotor	Decreased expression	27
GSTA2	*A	Thr112;Glu210	Reference	35
	*B	Ser112;Ala210	No change	36
GSTM1	*A	Lys173	Reference	49
	*B	Asp173	No change	49
	*O	Deletion	None	50
	*Ax2	Duplication	Hyper	51
GSTM3	*A	Reference	Reference	63,64
	*B	3 bp deletion	Altered transcription factor recognition	65
GSTM4	*A	Tyr2517	Reference	72
	*B	Cyt2517	No change	72
GSTO1	*A	Ala140;Glu155	Reference	80
	*B	Ala140;155 deleted	Increased	80
	*C	Asp140;Glu155	No change	80
GSTP1	*A	Ile105;Ala114	Reference	87,89
	*B	Val105;Ala114	Decreased	87,89
	*C	VaM05;VaM14	Decreased	87,89
	*D	Ile105;Val114	No change	88,89
GSTT1	*A	Thr104	Reference	98,101
	*B	Pro104	Deceased	98,101
	*O	Deletion	None	98
GSTT2	*A	Met139	Reference	98
	*B	Ile139	Not characterized	98
GSTZ1	*A	Lys32;Arg42;Thr82	Reference	107,108
	*B	Lys32;Gly42;Thr82	Decreased	108,109
	*C	Glu32;Gly42;Thr82	Decreased	108,109
	*D	Glu32;Gly42;Met82	Decreased	107

^aEnzyme activity is measured within each gene using *A, the first allele identified, as a reference.