I have a friend who told me she is not able to process THC. She has many allergies to all sorts of things; foods, environmental allergens, chemicals, flowers, and apparently THC. The blood test she took for allergens indicated that THC is one of the substances she cannot metabolize. This struck me as very weird. I had asked a number of people in the cannabis industry about it and no one had a good explanation. Then, I stumbled upon this fascinating article; how your DNA can affect how your body responds to cannabis. The article mainly focused on the CYP2C9 gene, but it also mentioned several other genes that affect the metabolism of cannabis.
So, what is CYP2C9? It is a gene that is produced by the liver and GI tract. It contains the instructions for creating the CYP2C9 enzyme. It is part of the Cytochrome P-450 family of enzymes; known as phase 1 detoxification molecules. Their job is to initiate the breaking down or metabolizing of many different substances that we either produce or ingest, including prescription drugs, cannabis smoke and caffeine. The chemical structure of CYP2C9 matches the structure of THC. When THC is present in your body and it encounters CYP2C9, THC transforms into other molecules, known as metabolites. A two-step breakdown process yields the non-psychoactive metabolite, THC-COOH.
FYI: when you are drug tested, it is the THC-COOH that shows up in your urine for which you may test positive. Here is the link to an article I previously wrote about how long THC stays in your body.
Why is this significant, you may be asking? Your unique CYP2C9 variant may affect your ability to metabolize THC in the following ways:
- It can determine how long the effects of THC last
- It can determine the intensity of the effects of THC
- It can determine how long the THC-COOH metabolite stays in your system in regards to drug testing. It can be anywhere from a few days to 30 days or more.
Here comes the really interesting part….there are different types of the CYP2C9 gene. Just like you have genes for the color of your eyes or the texture of your hair, your metabolism is determined, in part, by the variation in your CYP2C9 gene. They are called Single Nucleotide Polymorphisms (SNPs).
A SNP is a DNA sequence variation occurring when a single nucleotide adenine (A), thymine (T), cytosine (C), or guanine (G) differs between members of a species or paired chromosomes in an individual. For example, two sequenced DNA fragments from different individuals, AAGCCTA to AAGCTTA, contain a difference in a single nucleotide. In this case we say that there are two alleles: C and T. Almost all common SNPs have only two alleles. (ISOGG Wiki)
It is pretty complicated stuff, so if you want to know more about SNPs, here is a link to an in depth article about them. For my purposes, here is all you need to know about them:
- The variations in SNPs in your genes are not mutations. It is part of your unique make up.
- SNPs are distinguished by an “rs” number. An example would be rs1057910 which identifies that SNP in your DNA.
- One letter of your DNA sequence varies from one person to the next. A, C, G and T represent the 4 neucleotide bases of a DNA strand.
- Your allele type explains which version of the SNP you have. Some examples are AA, AC or CC.
- SNPs can change the function of each enzyme. They can cause poor reactions to NSAIDs or affect how you respond to blood thinners.
If you want to find out which type of CYP2C9 variant you have, you can find out through 23andMe. Go to tools>raw data section of the loginpage. Enter rs1057910 into the search bar and your variant will come up; AA, AC or CC.
Part II coming up with cannabis studies on different SNP variants of the CYP2C9!
Source: david-krantz.com, How DNA Affects Your Response To Cannabis – CPY2C9 Gene, December 4, 2017