CYP3A4

From SNPedia

The wikipedia article on CYP3A4 is a good resource to learn about the many drugs and chemicals that the protein encoded by this gene metabolizes. CYP3A4 is the most abundant detoxifying enzyme in the liver, and is responsible for helping to break down perhaps 60% of all known drugs. It also has an important role in the breakdown of testosterone.

One of the best known consequences of interfering with CYP3A4 function comes from the consequences of drinking grapefruit juice while taking medications metabolized by CYP3A4. Grapefruit juice inhibits the action of CYP3A4, which results in a higher concentration of many drugs within the body. This can have both positive and negative medical consequences. Wiki article OMIM

CYP3A4 is quite strongly conserved, and although some variants have been described, the in vivo activities of most corresponding proteins have not been shown to be different from wild-type CYP3A4*1. One variant that is actually nonfunctional, CYP3A4*20, is exceedingly rare (rs67666821).[PMID 16580902]

CYP3A4 is also located quite close to CYP3A5, and so some effects thought to be due to a CYP3A4 allele may actually due to a linked CYP3A5 allele. [1]

In African American males, CYP3A4 variation rs2740574 is associated with a ~10 fold higher risk of prostate cancer being of an aggressive form. [PMID 16414488]

CYP3A4 alleles and variants include the following:

Allele Name	Rs#	Comments	Platforms
CYP3A4*1	n/a	Actually a family of >18 "sub" alleles, with minor variations
CYP3A4*1B	rs2740574		23andMe v1, 23andMe v2, HumanOmni1Quad
CYP3A4*2	rs55785340	Also known as S222P
CYP3A4*3	rs4986910	Also known as M445T	23andMe v1, 23andMe v2, HumanOmni1Quad, Illumina Human 1M
CYP3A4*4	rs55951658	Also known as I118V
CYP3A4*5	rs55901263	Also known as P218R
CYP3A4*6	rs4646438	Frameshift; likely to be of lower activity
CYP3A4*7	rs56324128	Also known as G56D
CYP3A4*8	rs72552799	Also known as R130Q
CYP3A4*11	rs67784355	Also known as T363M
CYP3A4*12	rs12721629	Also known as L373F; formerly known as rs45614732	HumanOmni1Quad, Illumina Human 1M
CYP3A4*13	rs4986909	Also known as P416L	23andMe v1, 23andMe v2, HumanOmni1Quad, Illumina Human 1M
CYP3A4*14	rs12721634	Also known as L15P	23andMe v1, 23andMe v2, HumanOmni1Quad, Illumina Human 1M
CYP3A4*15A	rs4986907	Also known as R162Q	23andMe v1, 23andMe v2
CYP3A4*16	rs12721627	Also known as T185S	23andMe v2
CYP3A4*17	rs4987161	Also known as F189S	23andMe v1, 23andMe v2
CYP3A4*18	rs28371759	Also known as L293P	23andMe v1, 23andMe v2, HumanOmni1Quad, Illumina Human 1M
CYP3A4*19	rs4986913	Also known as P467S	23andMe v1, 23andMe v2, HumanOmni1Quad, Illumina Human 1M
CYP3A4*20	rs67666821	Nonfunctional; known as 1461_1462insA
CYP3A4*_11460A>G(K96E)	rs3091339		23andMe v1, 23andMe v2, Illumina Human 1M
CYP3A4*_14313G>A(E174H)	rs4986908		23andMe v1, 23andMe v2, HumanOmni1Quad, Illumina Human 1M
CYP3A4*_15635A>G(I193V)	rs3208361		23andMe v1, 23andMe v2, Illumina Human 1M
CYP3A4*_16907T>G(S252A)	rs3208363		23andMe v1, 23andMe v2, HumanOmni1Quad, Illumina Human 1M
CYP3A4*_20239G>A	rs2242480		23andMe v1, Illumina Human 1M
CYP3A4*_23139T>C(I431T)	rs1041988		23andMe v1, 23andMe v2