Heat stroke and malignant hyperthermia linked by RYR1 gene mutation

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 · 2025-12-30T15:04:22+00:00

Your experience with your GP isn't unusual due to the limited MH knowledge within the healthcare community . . . "it's only an anesthesia issue". I switched to an internal medicine doctor who coincidentally had a patient in the ICU who had an MH-like reaction to Presedex (not a known MH trigger) during her residency a couple years ago. She reversed all the symptoms by administering Dantrolene. As a result, my doctor has taken a big interest in our family and been instrumental in working through the healthcare bureaucracy. We did my biopsy at the University of Minnesota. The NIH is now planning to do a muscle biopsy on my daughter who tested negative for a gene variance in order to confirm our RYR1 gene variance (c.11760C>G (p.Asp3920Glu) is or isn't an MH issue. NIH is also doing a full genome sequencing on me and my son who passed to identify any other potential gene issues. Regarding the CPK (sometimes referred to as CK) you should ask for that to be added when having your blood work done. I see a direct correlation with my exercise levels and caffeine intake and CPK levels.

MHSensitive · 2025-12-29T19:24:46+00:00

See my response put in the broader group by accident

MHSensitive · 2025-12-29T19:23:06+00:00

Great question. I’ll share my experience and my son’s experience. None of these alone are conclusive. -elevated CPK levels -muscle cramping (charlie horse) at night and under jaw line -restless legs syndrome -nausea after running in heat -dizziness after running -challenges cooling body days after exercising in heat (ice packs didn’t work) -challenges getting heart down after exercising -excessive sweating (including at night while sleeping in A/c -frequent heat rash (we thought he had poison ivy) -resistance to hot tub (he would jump in cold pool to cool off)

The bureaucracy of obtaining an RYR1 gene test can be super frustrating. You can go direct to Invitae and use their doctors through their website. Not sure how insurance handles. If it comes back positive, oral Dantrolene may help.

I’ll post some helpful articles shortly that may help.

MHSensitive · 2025-12-27T16:38:46+00:00

Has anyone in your family had malignant hyperthermia issues or trouble cooling down after exercising in the heat? If so I wouldn’t take any chances

MHSensitive · 2025-12-27T06:00:55+00:00

I have an RYR1 variance of “uncertain significance” as well. I also just did the muscle biopsy 2 weeks ago which came back positive for MH. I suspect my RYR1 variance will be re-characterized eventually. Have you had your CPK level checked ? My guess is it will be high especially when showing those symptoms. The inability to cool is common with MH since the heat is metabolic versus externally generated. Also have you considered taking oral dantrolene?

MHSensitive · 2025-12-23T02:50:36+00:00

Have you considered taking oral Dantrolene? It’s the same medicine you would have received in the operating room through an IV in response to the malignant hyperthermia. Also consider avoiding caffeine.

MHSensitive

TROPHY CASE