Table 2.
Distribution of CYP2D6 genotype, metabolizer phenotype and activity score
| CYP2D6 genotype | CYP2D6 metabolizer phenotypea | CYP2D6 activity scoreb | All subjects n = 199 N (%) | India n = 3 N (%) | Peru n = 114 N (%) | Thailand n = 82 N (%) |
|---|---|---|---|---|---|---|
| *4/*4 | PM | 0 | 1 (0.5) | – | 1 (0.9) | – |
| *4/*41 | IM | 0.5 | 1 (0.5) | – | 1 (0.9) | – |
| *1/*4 | IM | 1.0 | 11 (5.5) | – | 8 (7.0) | 3 (3.7) |
| *10/*10 | IM | 1.0 | 19 (9.5) | – | – | 19 (23.2) |
| *10/*41 | IM | 1.0 | 2 (1) | – | – | 2 (2.4) |
| *2/*4 | IM | 1.0 | 3 (1.5) | – | 3 (2.6) | – |
| *41/*41 | IM | 1.0 | 2 (1) | – | – | 2 (2.4) |
| *1/*10 | EM | 1.5 | 15 (7.5) | – | – | 15 (18.3) |
| *1/*41 | EM | 1.5 | 6 (3) | – | 3 (2.6) | 3 (3.7) |
| *1/*9 | EM | 1.5 | 2 (1) | – | 2 (1.8) | – |
| *2/*10 | EM | 1.5 | 14 (7) | – | – | 14 (17.1) |
| *2/*41 | EM | 1.5 | 4 (2) | – | – | 4 (4.9) |
| *1/*1 | EM | 2.0 | 47 (23.6) | – | 35 (30.7) | 12 (14.6) |
| *1/*2 | EM | 2.0 | 45 (22.6) | 3 (100) | 40 (35.1) | 2 (2.4) |
| *2/*2 | EM | 2.0 | 27 (13.6) | – | 21 (18.4) | 6 (7.3) |
aCYP2D6 poor metabolizers (PM), intermediate metabolizers (IM), extensive metabolizers (EM)
bCYP2D6 activity score is the sum of the per-allele scores; a null allele having a score of 0, a deficient allele a score of 0.5 and a normal allele a score of 1 [12]