First Genomic Study of CHS Found Genetic Mutations That May Explain Who Gets It

The first genomic investigation of CHS found that patients carried significantly more mutations in genes affecting cannabinoid metabolism (CYP2C9), pain perception (TRPV1), dopamine signaling (DRD2), and other pathways compared to cannabis-using controls.

Russo, Ethan B et al.·Cannabis and cannabinoid research·2022·Preliminary EvidenceCross-Sectional
RTHC-04186Cross SectionalPreliminary Evidence2022RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Cross-Sectional
Evidence
Preliminary Evidence
Sample
N=585

What This Study Found

CHS patients showed significantly elevated mutations in COMT (OR 12.0), ABCA1 (OR 8.4), CYP2C9 (OR 7.8), DRD2 (OR 6.2), and TRPV1 (OR 5.8) compared to cannabis-using controls without CHS. 87.7% of patients improved with cannabis cessation, but most relapsed rapidly after resumption.

Key Numbers

585 screened, 28 CHS + 12 controls genotyped. COMT mutation OR: 12.0 (p=0.012). ABCA1 OR: 8.4 (p=0.012). CYP2C9 OR: 7.8 (p=0.043). DRD2 OR: 6.2 (p=0.031). TRPV1 OR: 5.8 (p=0.015). 93% used flower or concentrates, multiple grams/day. 15.6% had cannabis dependency diagnosis. 56.6% had withdrawal symptoms.

How They Did This

Online screening questionnaire with 585 respondents. 205 qualified as CHS pool, 54 as cannabis-using controls. 28 CHS patients and 12 controls completed genomic testing via saliva kits. Both groups were high-frequency users of THC-predominant cannabis.

Why This Research Matters

CHS affects some heavy cannabis users but not others. This study provides the first genetic evidence explaining this selective vulnerability, pointing to specific metabolic and receptor genes that could eventually enable genetic screening or targeted treatments.

The Bigger Picture

If replicated, these genetic findings could transform CHS from a diagnosis of exclusion to one with biomarkers. The involvement of CYP2C9 (cannabinoid metabolism) and TRPV1 (pain/heat sensing) is particularly elegant, as it connects to known CHS features (metabolic sensitivity and hot bathing behavior).

What This Study Doesn't Tell Us

Very small genomic sample (28 patients, 12 controls) limits statistical power. Online recruitment introduces selection bias. Only 28 of 99 willing patients returned genetic kits. The study was not designed to establish clinical-grade genetic associations.

Questions This Raises

  • ?Would a larger genomic study confirm these mutations?
  • ?Could genetic screening identify cannabis users at risk for CHS before symptoms develop?
  • ?Do these mutations affect response to CHS treatments?

Trust & Context

Key Stat:
COMT mutation 12x more common in CHS patients vs cannabis-using controls
Evidence Grade:
Preliminary: first-of-its-kind genomic analysis but limited by very small sample size (28 patients, 12 controls).
Study Age:
Published in 2022.
Original Title:
Cannabinoid Hyperemesis Syndrome Survey and Genomic Investigation.
Published In:
Cannabis and cannabinoid research, 7(3), 336-344 (2022)
Database ID:
RTHC-04186

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

A snapshot of a population at one point in time.

What do these levels mean? →

Frequently Asked Questions

Why do some heavy cannabis users get CHS and others don't?

This study suggests genetics play a role. CHS patients had significantly more mutations in genes affecting how their bodies process cannabinoids (CYP2C9), sense pain and temperature (TRPV1), and regulate dopamine (DRD2), creating a biological vulnerability.

Could a genetic test predict CHS risk?

Not yet. The sample was too small for clinical application. But if these findings are confirmed in larger studies, genetic screening could eventually identify cannabis users at risk before they develop the severe vomiting episodes.

Read More on RethinkTHC

Cite This Study

RTHC-04186·https://rethinkthc.com/research/RTHC-04186

APA

Russo, Ethan B; Spooner, Chris; May, Len; Leslie, Ryan; Whiteley, Venetia L. (2022). Cannabinoid Hyperemesis Syndrome Survey and Genomic Investigation.. Cannabis and cannabinoid research, 7(3), 336-344. https://doi.org/10.1089/can.2021.0046

MLA

Russo, Ethan B, et al. "Cannabinoid Hyperemesis Syndrome Survey and Genomic Investigation.." Cannabis and cannabinoid research, 2022. https://doi.org/10.1089/can.2021.0046

RethinkTHC

RethinkTHC Research Database. "Cannabinoid Hyperemesis Syndrome Survey and Genomic Investig..." RTHC-04186. Retrieved from https://rethinkthc.com/research/russo-2022-cannabinoid-hyperemesis-syndrome-survey

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.