CYP2C19

From SNPedia

CYP2C19 is a member of the IIC subfamily of the cytochrome p450 genes, responsible for metabolizing some hormones (such as estrogens) and several commonly prescribed drugs, including anti-epileptics (such as diazepam, phenytoin, and phenobarbitone), anti-depressants (such as amitriptyline and clomipramine), the anti-platelet drug clopidogrel (Plavix), the anti-ulcer proton pump inhibitors like omeprazole (trade names Losec and Prilosec), esomeprazole (trade name Nexium), and lansoprazole (Prevacid), and even some hormones (like progesterone).

Asians and Pacific Islanders have a higher incidence of nonfunctional CYP2C19 variants, which may affect treatment for malaria. The antimalarial drug proguanil is metabolized by both CYP2C19 and CYP2D6. [[1]] [[2]]

Generally, with respect to CYP2C19, individuals are classified as rapid metabolizers if they are homozygous for the CYP2C19*1 allele (ie they are CYP2C19*1/CYP2C19*1), intermediate metabolizers if they have one CYP2C19*1 allele plus one variant allele (such as CYP2C19*2 or CYP2C19*3), and poor metabolizers if they carry two copies of a variant. Effective doses are higher for individuals who are poor metabolizers and thus treatment success is higher as well. [PMID 15952098]

SNPs in CYP2C19 include:

Allele Name	Rs#	Comments	Platforms
CYP2C19*1	n/a	Wild-type/normal, hence no rs#; genoset gs150
CYP2C19*2	rs4244285	nonfunctional	23andMe v2, HumanOmni1Quad
CYP2C19*2B	rs17878459	nonfunctional	23andMe v1, 23andMe v2, HumanOmni1Quad
CYP2C19*3	rs4986893 or rs57081121	poor metabolism of compounds like proguanil and therefore with implications for malaria prophylaxis	23andMe v1, 23andMe v2, HumanOmni1Quad and
CYP2C19*4	rs28399504	nonfunctional	23andMe v1, Illumina Human 1M, 23andMe v2, HumanOmni1Quad
CYP2C19*5	rs56337013	poor metabolizer
CYP2C19*6	rs72552267	nonfunctional
CYP2C19*7	rs72558186	nonfunctional
CYP2C19*8	rs41291556	nonfunctional	23andMe v2
CYP2C19*9	rs17884712		23andMe v1, 23andMe v2
CYP2C19*10	rs6413438		23andMe v1, 23andMe v2, HumanOmni1Quad, Illumina Human 1M
CYP2C19*11	rs58973490
CYP2C19*12	rs55640102
CYP2C19*13	rs17879685		23andMe v1, 23andMe v2, HumanOmni1Quad, Illumina Human 1M
CYP2C19*14	rs55752064
CYP2C19*15	rs17882687
CYP2C19*17	rs12248560	ultra-rapid metabolizer	23andMe v2
CYP2C19_80161G>A(V331I)	rs3758581		23andMe v2
CYP2C19_90052delG(G439-)	rs5787121		23andMe v1, 23andMe v2
hCV34328665	rs72558185

CYP2C19 allele nomenclature http://www.cypalleles.ki.se/cyp2c19.htm

Promethease checks this via genosets:

• gs150 CYP2C19 normal/rapid metabolizer (most likely)
• gs151 CYP2C19 Intermediate Metabolizer
• gs152 CYP2C19 Poor Metabolizer
• gs153 CYP2C19 Extensive or Ultra-Fast Metabolizer