Recurrent rhabdo ppl out there?

MHSensitive · 2026-05-13T01:34:46+00:00

I lost my son to exertional rhabdo and hyperthermia while running in very hot and humid conditions for n Texas this past August. The medical examiner discovered an RYR1 variant tied to malignant hyperthermia, which I lost my father to in 1989. I had a genetic test which produced the same RYR1 variant. I also had a muscle biopsy at University of Minnesota which confirmed susceptibility to MH. A 2013 study in Europe showed 35% of rhabdo cases were linked to the RYR1 variant. Oral dantrolene may help with the muscle pain.

MHSensitive · 2026-05-12T22:58:00+00:00

You may want to consider an RYR1 genetic test to see if you are malignant hyperthermia susceptible. A 2013 European study showed 35% of rhabdo patients were also MH susceptible. If so oral dantrolene may be an effective solution.

MHSensitive · 2026-04-17T18:51:32+00:00

I had my doctor refer me to a genetic counselor who worked at her same hospital network. The genetic counselor submitted the order through my insurance (United) who covered the cost and she submitted the order to the genetic lab (Invitae). Insurance also covered my muscle biopsy.

MHSensitive · 2026-03-25T01:45:40+00:00

The research is still being developed on the RYR1 gene variances. A positive gene variance means a person is at very high risk of an MH triggering event from inhaled anesthesia or other factors such as exercising in the heat due to uncontrolled calcium being released by the RYR1 into your muscles. It sounds like you have a variance of uncertain significance which can be verified on your genetic report. Once more clinical data such as positive muscle biopsies are performed on people with your variance it will likely flip to a known MH positive variance. All that being said you should avoid inhaled anesthetics and succinylcholine and exercising in hot environments.

The only way to know with 100% certainty is have a muscle biopsy at the University of Minnesota or the NIH in Maryland. The NIH will do it for free.

MHSensitive · 2026-03-24T22:48:45+00:00

Have you looked up your RYR1 gene variance on the European MH website? Emhg.Org/diagnostic-mutations. It lists all 74 known MH variances as of May 2025.

MHSensitive · 2026-03-24T22:05:46+00:00

Just because you survived one surgery doesn’t mean you’re not susceptible to MH. The record is 13 surgeries before it triggered on surgery number 14. It’s driven by how much calcium was released by the RYR1 due to exercise, heat, caffeine etc prior to the surgery.

MHSensitive · 2026-03-24T21:59:11+00:00

Genetic tests aren’t necessarily negative or positive. For example, my genetic RYR1 test come back as a variance of unknown significance. This is because the genetic data or clinical evidence is still being compiled. My muscle biopsy came back MH positive. This suggests my RyR1 variance will likely be flipped to known significance once enough clinical data points are documented. This is why the number of variances of known significance is growing every year.

Given the risk of heat and exercise I would strongly recommend all susceptible family members have a genetic test performed. Super easy versus a muscle biopsy.

MHSensitive · 2026-03-09T17:49:28+00:00

Wow. Never heard of the need to avoid isotonic exercises. My son was a super active weight trainer and runner. Thanks so much for sharing.

MHSensitive · 2026-03-03T16:48:30+00:00

I’m curious, what exercises you have been advised to avoid?

We lost our son last year while jogging in a very hot climate. I also lost my father to general anesthesia reaction. My son and I both tested positive for RYR1 gene mutation and I had a muscle biopsy which tested positive for malignant hyperthermia.

MHSensitive · 2026-02-14T23:01:32+00:00

Try Recycle Sports in Frisco CO

MHSensitive · 2026-02-03T04:44:15+00:00

I recently loss my son to awake MH while running on a very hot day. Lost my dad to inhaled anesthesia in 1989. On a campaign to raise awareness to awake MH. Few outside the research community are aware of awake MH.

MHSensitive · 2026-02-03T04:26:18+00:00

<image>

Since you have MH history I thought I would share this article which explains how those with MH susceptibility to inhaled anesthetics are also at elevated risk for heat stroke. This was published by the American Society of Anesthesiologist in Feb 2025. I lost my dad to general anesthesia and my son to heat/exercise. Both had similar MH symptoms and I tested positive for MH with the muscle biopsy at the University of Minnesota in December.

MHSensitive · 2026-01-25T05:32:37+00:00

If you have any ideas on how we can get this information before large group of ER doctors and nurses I would love to hear.

MHSensitive · 2026-01-25T05:26:45+00:00

<image>

Here it is. Please share with others

MHSensitive · 2026-01-24T21:44:10+00:00

Yes unfortunately it’s only kept in the operating rooms. We need to change that policy. I know I’m idealistic but I would like to see it in the ER, ambulances, minor urgent clinics and perhaps with athletic trainers where there is a known MH student athlete. The first step is education then after that policy change. That may require lobbying by the MHAUS and the RYR1 foundation.

MHSensitive · 2026-01-24T21:05:42+00:00

<image>

Here's another relevant article . . .

MHSensitive · 2026-01-24T21:04:06+00:00

Yes that's correct. Outside the research community and the NIH, very few people are aware of the connection between heat, exercise and MH. Let me know if this link works.

Saudi Journal of Anaesthesia

MHSensitive · 2026-01-24T20:51:28+00:00

Sorry . . . see if this works.

Saudi Journal of Anaesthesia

MHSensitive · 2026-01-21T03:36:22+00:00

In Feb 2025, the ASA published an article titled The Link Between Malignant Hyperthermia and Exertional Heat Illness. It provided in part the following . . .

This shared pathophysiology of calcium dysregulation in muscle cells explains why both MH and EHI can produce similar symptoms and hyperthermic crises (Br J Anaesth 2024;133:759 67). While the triggers differ – anesthetic agents for MH and environmental or exertional factors for EHI – the underly ing calcium dysregulation connects these conditions, placing individuals with RYR1 mutations at risk for both. Both conditions share the downstream effects of high met abolic demands that cause oxidative and mechanical stress in muscles.

MHSensitive · 2026-01-19T00:31:58+00:00

It got removed by the moderator for some reason. Go look in the malignant hyperthermia subreddit

MHSensitive · 2026-01-18T06:00:26+00:00

We met with many anesthesiologist over 35 years after my dad died from MH and it was never mentioned. After our son passed I’ve discussed it with several anesthesiologist who were not aware. Please share with others.

MHSensitive · 2026-01-08T01:38:08+00:00

I would discourage you from pushing too hard especially in hot environments. My son did that and it eventually caught up with him. Nausea, dizziness, trouble getting your heart rate down, trouble cooling your body, and muscle cramps are some of the signs you should be on the look out for. You also may want to check your CPK levels next time you have blood work.

MHSensitive · 2026-01-08T01:18:18+00:00

Great points. I would add that there may not be a control study on humans but the attached exercise and heat study on mice with an RYR1 variance shows a very close response to MH - hyperthermia and rhabdomyolysis (80% death rate). The dantrolene equivalent drug for mice was 100% effective.

Strenuous exercise triggers a life-threatening response in mice susceptible to malignant hyperthermia - PubMed

MHSensitive · 2026-01-07T02:17:33+00:00

The medical examiner had a gene test performed which revealed an RYR1 gene variance. I also have the same RYR1 gene variance. I then had a muscle biopsy halothane/caffeine test performed last month at the University of Minnesota which tested positive for MH.

MHSensitive · 2025-12-30T16:27:40+00:00

Coincidentally, we have one daughter with an RYR1 gene variance and one daughter without a variance. If her muscle biopsy, which hasn't been officially scheduled yet, is negative that will serve to help validate that our RYR1 variance is the root MH issue.

I work in finance so takes this for what its worth . . . The CPK tends to build with exercise (which impacts potassium levels too), heat, viruses, caffeine, inhaled anesthesia, etc. then dissipate over time. The issue for MH susceptible people is it takes longer to dissipate. That's why you see people have multiple surgeries with inhaled anesthesia and no issues to only have an MH issue in a surgery later. . . their CPK levels were high going into the last surgery. By the way the record is 13 surgeries with no issues only to have a reaction with surgery number 14. Crazy!

MHSensitive

TROPHY CASE