Can genetic testing help diagnose CHS?

As the awareness of cannabinoid hyperemesis syndrome (CHS) grows among both doctors and patients, together we will be increasingly able to identify a condition that has historically been difficult to diagnose. After all, it doesn’t seem intuitive that cannabis can cause many of the symptoms it is used to treat.

Researchers are taking current understanding of this serious and often debilitating condition a step further by trying to pinpoint genetic markers that could be used to help diagnose CHS more easily. This could prevent potentially vulnerable people from developing it in the first place.

Below is how CHS relates to genetics and what is being done in the medical world to combat the outbreak of the cannabis-based disease.

What is cannabinoid hyperemesis syndrome?

Cannabinoid hyperemesis syndrome is still not widely known or fully understood. It is a condition characterized by a strong and often persistent sensitivity to THC – and possibly other cannabinoids. CHS causes persistent abdominal pain, cramps, nausea, and vomiting when cannabis is consumed.

What causes CHS?

While our understanding of the condition is still developing, CHS appears to be most prevalent in people who regularly consume highly potent cannabis and cannabis products over an extended period of time. What happens in the body is long-term and intense stimulation of the endocannabinoid system (ECS), along with other receptors and systems outside of the ECS.

While medical science is still working to uncover the more complex and nuanced factors that contribute to CHS, according to Dr. Ethan Russo, a renowned pioneer in cannabis research, rightly say that CHS is not a functional gastrointestinal disorder, but rather a “manifestation of gene and environmental interaction in a rare genetic disease that is exposed by excessive THC exposure”.

What does not cause CHS? Pesticides.

Dr. Russo thinks it’s important to dispel the myth that CHS is caused by pesticides or neem oil used in growing crops. “That’s just not an explanation,” said Dr. Russo. “There are more pesticides used today than when CHS was discovered, and the responses from pesticides are very different from CHS. In addition, synthetic cannabinoids, which are quite potent, have been shown to induce CHS – and while they are not pure, they do not contain pesticides. “

The difficulty and high cost of diagnosing CHS

The main symptoms of CHS – cyclical abdominal cramps, nausea, and vomiting – are not limited to this condition, which makes it difficult to diagnose CHS. For this reason, CHS is considered by doctors to be a “diagnosis of exclusion” or a diagnosis made when all other probable causes are ruled out.

According to a 2019 study estimate, the average emergency room required a whopping $ 76,920.92 in testing costs to diagnose CHS, while a 2018 study brought the average patient cost for a CHS-related emergency room visit to over $ 4,600. Dollars appreciated.

One thing that makes CHS easier to localize is the habitual or ritual showering or bathing behavior, which patients learn to temporarily relieve their symptoms. Another is relief from topical application of capsaicin cream, which has a physiologically similar effect to a hot shower or bath.

While hot baths and showers, topical application of capsaicin creams, and sometimes even antipsychotics can all be used to relieve symptoms, currently the only known cure for CHS is complete abstinence from cannabis.

How common is CHS?

Historically, there have been inconsistent reports of CHS diagnoses. People with CHS often end up in emergency rooms when the cyclical vomiting becomes severe and their health is at risk. Due to the fact that CHS is not widely known or understood in the medical community, and the fact that most doctors receive little to no training or education in the field of the endocannabinoid system, CHS is often misdiagnosed or as caused by a cannabis use disorder caused called.

Not only is this worrying because it wrongly links CHS to substance abuse in the medical community, but it also means that we don’t know exactly how prevalent CHS is among cannabis users and patients. According to Dr. Russo is probably much more common in CHS than we realize.

An epidemiological study conducted at Bellevue Hospital in New York City looked at over 2,000 patients admitted to the emergency room who presented with cyclical vomiting. They found that over 30% of these patients who used cannabis for more than 20 days a month and found relief from hot showers were likely to have CHS. Extrapolated to the US population, they estimated that 2.75 million Americans could have CHS.

What does genetics have to do with CHS?

The more we learn about cannabis, cannabinoids, and human physiology, the more accurate our understanding of how plants interact with and affect our bodies.

While not much research is specifically focused on CHS, thanks to the pioneering work of geneticists and cannabis researchers, we are beginning to create a tentative picture of how genetics could affect the development of CHS.

In collaboration with cannabis genetics testing company Endocanna Health, Dr. Russo reviewed the genetics of 28 patients with cannabis hyperemesis syndrome. What they found were five gene mutations known as single nucleotide polymorphisms (or SNPs) with plausible causal roles in CHS.

These five genes affect everything from dopamine activity to pain responses, mood regulation, and bowel disorders:

COMT gene

The COMT (catechol-O-methyltransferase) gene provides instructions on how to make an enzyme that helps break down stimulating neurotransmitters like dopamine in the brain. A malfunction in these genes can lead to an excess of dopamine, which can lead, for example, to more risk-taking and less inhibition in things like gambling or substance abuse.

According to Dr. Russo, COMT has also been linked to depression, brooding, obsessive-compulsive disorder, ADHD, and psychosis. 56 percent of CHS patients in the study had mutations in this gene.

TRPV1 gene

This gene is involved in the development of TRPV1 receptors, which are activated by a variety of physical and chemical stimuli – especially those involved in heat perception.

Activation of the TRPV1 receptors often results in painful and burning sensations, and by interacting with TRPV1, cannabinoids can provide pain relief. In Russo’s study, 71% of patients had mutations in this gene, which helps shed some light on the abdominal pain, bowel disorders, and relief from capsaicin creams and hot showers common in people with CHS.

CYP2C9 gene

This gene provides instructions for making the CYP2C9 enzyme, which is involved in breaking down steroid hormones and fatty acids. It is also involved in the metabolism of prescription drugs and THC. Forty-six percent of the patients in Russo’s study had mutations in this gene, and he suspects that this mutation could inhibit the breakdown of THC, which would lead to higher than normal levels in the body.

At high concentrations, THC can produce a two-phase response, meaning that at lower concentrations or doses it can do just the opposite. This would make understandable the nausea and vomiting that we don’t normally associate with a cannabis experience.

DRD2 gene

The DRD2 gene is responsible for the formation of the dopamine receptor D2. This receptor is the target of many antipsychotics and was found to have mutations in 60% of CHS patients in Russo’s study. Drugs that target D2 receptors are proemetic, which means that they can induce nausea and vomiting, and often affect bowel motility. Therefore, it makes sense that there is a malfunction in the gene coding for this receptor in CHS.

These receptors have also been linked to depression, anxiety, nicotine use, Tourette’s syndrome, and chronic pain, which could indicate other vulnerabilities in CHS patients.

ABCA1 gene

The ABCA1 gene is part of a family of genes responsible for making proteins that act as carriers for other molecules to cross cell membranes.

This gene mutation was present in 68% of CHS patients in Russo’s study, and although more research is needed, he believes it could signal that CHS patients are more prone to coronary artery disease (CHD), heart attacks, and type II diabetes , and Alzheimer’s.

The future of CHS diagnostics

Russo’s study is the first of its kind and the largest to date specifically looking at cannabinoid hyperemesis syndrome.

While there is certainly more to be discovered in and around the genetic basis of CHS, this study provides us with several pointers and a good set of tests that can be used to screen people for CHS more effectively and cheaply and to help high-powered cannabis consumers understand if they might be prone to CHS. This could save a lot of time and money for both doctors and patients in the emergency room.

Companies like Endocanna Health are betting on the future of cannabis genetic testing for both patients and consumers. While Dr. Russo was skeptical at first, but saw the potential of this area to really help people. He now works as an unpaid scientific advisor at Endocanna and looks promising in genetic testing.

“This is a relatively new technology, but I’ve looked at a lot of reports and the correlations seem to be very good. I believe this will be helpful to a lot of people. I started out as a skeptic, but I think this is a useful technology right now and it will improve the more it is used. “

Featured image by Gina Coleman / Weedmaps