Table 2 Overview of the selected SNPs, their effect on enzyme function and definition of risk alleles

Biotransformation Phase I

CYP1A2

A > C-154

(1)

Higher inducibility

-154 C

CYP1A1

T > C3801

(4)

3801 C

I462V

(4)

462 V

Increased formation of reactive metabolites (phase I enzymes)

T461N

(4)

Higher enzyme activity

461 N

CYP2E1

G > T-70

(4)

-70 T

CYP3A4

A > G-391

(4)

-391 G

Biotransformation Phase II

GSTM1

Del

(1)

Deletion, no enzyme activity

Del

GSTT1

Del

(1)

Del

GSTP1

I105V

(1)

105 V

Decreased detoxification of reactive metabolites (phase II enzymes)

A114V

(1)

114 V

NAT2

I114T

(1)

Decreased enzyme activity

114 T

R197Q

(1)

197 Q

G286E

(1)

286 E

DNA Repair

BRCA2

5'UTR (A-26G)

(2)

Modulated expression

A -26

N372H

(2)

Decreased enzyme activity

372 H

Decreased DNA repair

XRCC1

R194W

(2)

Increased enzyme activity

R 194

R280H

(2)

Decreased enzyme activity

280 H

XRCC3

T241M

(2)

241 M

XPD

K751Q

(2)

751 Q

R156R

(2)

Decreased enzyme activity

156 R

Decreased DNA repair

APE1

D148G

(3)

148 G

OGG1

S326C

(2)

326 C

Oxidative Stress

mnSOD

V16A

(3)

Decreased enzyme activity

16 A

CAT

C > T-262

(3)

Lower catalase activity

-262 T

Decreased oxidative stress defense

NQO1

P187S

(3)

Decreased enzyme activity

187 S

R139W

(3)

139 W

MPO

G > A-463

(4)

Higher enzyme activity

G -463

Higher production of free radicals

GPX1

P198L

(3)

Less efficient final GSH peroxidaxe complex

198 L

Impaired GSH metabolism; higher oxidative stress