Volunteers: We are seeking volunteers who are willing to complete an online survey that is expected to take between 15 and 30 minutes to complete. We are looking for both individuals who know that they have an RYR1 variant, persons with a history of malignant hyperthermia, and persons who have had episodes of tea or cola-colored urine (rhabdomyolysis). We also need as volunteers persons with none of these who will be the control subjects in the study so that we can compare persons likely to have RYR1 variants with persons who are not likely to have RYR1 variants. Symptoms of RYR1 variants may be seen in early childhood and for that reason we are looking for volunteers as young as 5 years of age. All ages above age 5 are sought for volunteers. The informed consent contains details for enrolling minors, but basically a minor has to be willing to participate (to assent) to be in the study. A parent or guardian may complete the form for minors who are too young or otherwise unable to complete the questionnaire

Please go to the page with the informed consent next.