Summary of genetic polymorphism in exon 4 of cytochrome P450 and mean daily warfarin dose (μg/kg per day) in 89 Chinese patients
| Codon 181 . | Codon 184 . | Codon 192 . | Codon 208 . | Mean dose ± SEM . | N . |
|---|---|---|---|---|---|
| Ile | His | Gln | Leu | 72.6 ± 14.0 | 4* |
| Ile | His | Gln | Leu/Val | 53.8 ± 2.9 | 50* |
| Ile | His | Gln | Val | 48.1 ± 3.5 | 15* |
| Ile | His | Gln/Pro | Leu/Val | 57.1 ± 5.5 | 6 |
| Ile | His | Gln/Pro | Val | 63.6 ± 0.0 | 1 |
| Ile | His/Pro | Gln/Pro | Leu/Val | 47.4 ± 16.5 | 4 |
| Ile | His/Pro | Gln/Pro | Val | — | 1 |
| Ile/Leu | His | Gln/Pro | Leu/Val | 87.6 ± 4.9 | 4 |
| Ile/Leu | His/Pro | Gln | Leu/Val | 95.3 ± 4.4 | 2 |
| Ile/Leu | His/Pro | Gln/Pro | Leu | 91.0 ± 0.0 | 1 |
| Ile/Leu | His/Pro | Gln/Pro | Leu/Val | 100.8 ± 0.0 | 1 |
| Codon 181 . | Codon 184 . | Codon 192 . | Codon 208 . | Mean dose ± SEM . | N . |
|---|---|---|---|---|---|
| Ile | His | Gln | Leu | 72.6 ± 14.0 | 4* |
| Ile | His | Gln | Leu/Val | 53.8 ± 2.9 | 50* |
| Ile | His | Gln | Val | 48.1 ± 3.5 | 15* |
| Ile | His | Gln/Pro | Leu/Val | 57.1 ± 5.5 | 6 |
| Ile | His | Gln/Pro | Val | 63.6 ± 0.0 | 1 |
| Ile | His/Pro | Gln/Pro | Leu/Val | 47.4 ± 16.5 | 4 |
| Ile | His/Pro | Gln/Pro | Val | — | 1 |
| Ile/Leu | His | Gln/Pro | Leu/Val | 87.6 ± 4.9 | 4 |
| Ile/Leu | His/Pro | Gln | Leu/Val | 95.3 ± 4.4 | 2 |
| Ile/Leu | His/Pro | Gln/Pro | Leu | 91.0 ± 0.0 | 1 |
| Ile/Leu | His/Pro | Gln/Pro | Leu/Val | 100.8 ± 0.0 | 1 |
Codons denoted by two amino acids represent heterozygosities at those loci. Warfarin dose of one patient (denoted by —) was unavailable.
At codon 208, heterozygous 608TTG > GTG (Leu208Val) and homozygous 608G > TG (Val208) appeared to require lower warfarin doses than the wild-type carriers (Leu208). However, the difference was not statistically significant (P = .2). N indicates number of patients in each category.