Table 2

Frequencies of CYP1A1 and CYP2E1 gene polymorphisms in different ethnic groups

PolymorphismCaucasians No. (%)Asians No. (%)Africans No. (%)
CYP1A1 Msp1 (CYP1A1*2A, CYP1A1*2B)
 No.4453638461
 Homozygous (wild-type)3670 (82.4)268 (42)268 (58.1)
 Heterozygous729 (16.4)281 (44)166 (36)
 Homozygous (variant)54 (1.2)89 (14)27 (5.9)
CYP1A1 exon 7 (CYP1A1*2B, CYP1A1*2C)
 No.47901132481
 Homozygous (wild-type)4319 (90.2)670 (59.2)456 (94.8)
 Heterozygous444 (9.3)407 (36)25 (5.2)
 Homozygous (variant)27 (0.6)55 (4.9)0 (0)
CYP2E1 Rsa1 (CYP2E1*5A, CYP2E1*5B)
 No.1454719NAa
 Homozygous (wild-type)1344 (92.4)428 (59.5)
 Heterozygous109 (7.5)258 (35.9)
 Homozygous (variant)1 (0.1)33 (4.6)
CYP2E1 DraI (CYP2E1*5A, CYP2E1*6)
 No.1360286NA
 Homozygous (wild-type)1162 (85.4)138 (48.3)
 Heterozygous187 (13.8)121 (42.3)
 Homozygous (variant)11 (0.8)27 (9.4)
  • a NA, not available.