Table 1.
CYP2C19 gene variants.
| Allele | Characteristic SNPa | Functional change | References | ||
|---|---|---|---|---|---|
| cDNA | Gene | Effect | |||
| CYP2C19*1 | None1 | None | None | Normal | Romkes et al., 1991 |
| CYP2C19*2 | 681G>A2 | 19154G>A | Splicing defect | Non-functional | De Morais et al., 1994b; Ibeanu et al., 1998b; Fukushima-Uesaka et al., 2005; Lee et al., 2009; Satyanarayana et al., 2009a |
| CYP2C19*3 | 636G>A3 | 17948G>A | Premature stop codon (W212X) | Non-functional | De Morais et al., 1994a; Fukushima-Uesaka et al., 2005 |
| CYP2C19*4 | 1A>G4 | 1A>G | GTG initiation codon | Non-functional | Ferguson et al., 1998; Scott et al., 2011 |
| CYP2C19*5 | 1297C>T5 | 90033C>T | R433W | Non-functional | Xiao et al., 1997; Ibeanu et al., 1998a |
| CYP2C19*6 | 395G>A | 12748G>A | R132Q | Non-functional | Ibeanu et al., 1998b |
| CYP2C19*7 | 19294T>A | Splicing defect | Non-functional | Ibeanu et al., 1999 | |
| CYP2C19*8 | 358T>C | 12711T>C | W120R | Decreased in vitro | Ibeanu et al., 1999 |
| CYP2C19*9 | 431G>A | 12784G>A | R144H | Decreased in vitro | Blaisdell et al., 2002 |
| CYP2C19*10 | 680C>T | 19153C>T | P227L | Decreased in vitro | Blaisdell et al., 2002 |
| CYP2C19*11 | 449G>A | 12802G>A | R150H | Similar to wild type in vitro | Blaisdell et al., 2002 |
| CYP2C19*12 | 1473A>C | 90209A>C | X491C; 26 extra amino acids | Unstable in vitro | Blaisdell et al., 2002 |
| CYP2C19*13 | 1228C>T | 87290C>T | R410C | Similar to wild type in vitro | Blaisdell et al., 2002 |
| CYP2C19*14 | 50T>C | 50T>C | L17P | Not determined | Blaisdell et al., 2002 |
| CYP2C19*15 | 55A>C | 55A>C | I19L | Not determined | Blaisdell et al., 2002 |
| CYP2C19*16 | 1324C>T6 | 90060C>T | R442C | Not determined | Morita et al., 2004 |
| CYP2C19*17 | 3402C>T; −806C>T | Increased transcription in vitro; Should not be termed Ultrarapid (UM) | Sim et al., 2006 | ||
| CYP2C19*18 | 986G>A | 80156G>A; 87106T>C | R329H | Not determined | Fukushima-Uesaka et al., 2005 |
| CYP2C19*19 | 151A>G | 151A>G; 87106T>C | S51G | Not determined | Fukushima-Uesaka et al., 2005 |
| CYP2C19*207 | 636G>A | 17948G>A | Premature stop codon (W212X) and D360N | Non-functional | Fukushima-Uesaka et al., 2005 |
| CYP2C19*218 | 681G>A | 19154G>A; –98T>C | splicing defect and A161P | Non-functional | Fukushima-Uesaka et al., 2005; Satyanarayana et al., 2009a |
| CYP2C19*22 | 557G>C | 17869G>C | R186P | Not determined | Matimba et al., 2009 |
| CYP2C19*23 | 271G>C | 12455G>C | G91R | Not determined | Zhou et al., 2009 |
| CYP2C19*24 | 1004G>A; 1197A>G | 80174G>A; 87259A>G | R335Q | Not determined | Zhou et al., 2009 |
| CYP2C19*25 | 1344C>G | 90080C>G | F448L | Not determined | Zhou et al., 2009 |
| CYP2C19*26 | 766G>A | 19239G>A | D256N | Decreased in vitro | Lee et al., 2009 |
| CYP2C19*27 | –1041G>A | Decreased in vitro | Drögemöller et al., 2010 | ||
| CYP2C19*28 | 1120G>A | −2020C>A; −1439T>C; 80290G>A | V374I | No significant decrease in vitro | Drögemöller et al., 2010 |
Only major SNP or alteration(s) responsible for the phenotype of the corresponding allele are shown. Adapted from http://www.cypalleles.ki.se/
The presence of additional SNP can further sub-classify individuals as *1B (99C>T; 991A>G) or *1C (991A>G). This results in an I331V change but does not alter activity.
The presence of additional SNP can further sub-classify individuals as *2A, *2B, *2C, and *2D. Of these variants *2C and *2D harbor a SNP in the 5′ promoter region (−98T>C) that may have a functional effect.
The presence of additional SNP can further sub-classify individuals as *3A (1251A>C) and *3B (1078G>A; 1251A>C).
The presence of −3402C>T; −806C>T SNP in the promoter can further sub-classify individuals as *4B.
The presence of 99C>T; 991A>G, can further sub-classify individuals as *5B.
Existence of the CYP2C19 *2 polymorphism 681G>A on the same allele cannot be excluded.
Also known as CYP2C19 *3B.
Also known as CYP2C19 *2C.