Table 2.
Gene variant functions and carrier frequencies by race
| Gene and SNP nucleotide designation | Gene function/variant function | European-Americans |
African-Americans |
||
|---|---|---|---|---|---|
| Carrier frequency (n) | Proportion missing (n)a | Carrier frequency (n) | Proportion missing (n)a | ||
| COMT Val158Met (rs4680) | Metabolism of estrogens and neurotransmitters/decreased enzyme activity | 0.747 (115)b | 0.019 (3) | 0.571 (76),b P = 0.001c | 0.043 (6) |
| CYP1A2*1F (rs762551) | Metabolism and hydroxylation of estrogens, activity induced by tobacco and estrogens/increased inducibility and metabolism of estrogens | 0.890 (137)b | 0.019 (3) | 0.860 (117),b P = 0.4c | 0.022 (3) |
| CYP1B1*3 (Leu432Val, rs1056836) | Metabolism and hydroxylation of estrogens, highly expressed in the ovary, induced by tobacco and involved in metabolic activation of smoking toxins/increased metabolic activity | 0.673 (103)b | 0.026 (4) | 0.941 (128),b P < 0.0001c | 0.022 (3) |
| CYP1B1*4 (Asn452Ser, rs1800440) | Metabolism and hydroxylation of estrogens/increased metabolic activity | 0.303 (46)b | 0.026 (4) | 0.096 (13),b P < 0.0001c | 0.022 (3) |
| CYP3A4*1B (rs2740574) | Metabolism and hydroxylation of estrogens, activation of tobacco-related toxins/increased metabolic activity | 0.844 (114)b | 0.013 (2) | 0.085 (13),b P < 0.0001c | 0.029 (4) |
a
Proportion of subjects for whom genotyping could not be performed.
b
Indicates no deviation from Hardy-Weinberg proportions at the P < 0.05 level.
c
P value for difference in carrier frequency across race.