Hypokalemic periodic paralysis associated with malignant hyperthermia

Hypokalemic periodic paralysis is in most cases related to mutations within the dihydropyridine receptor gene. Susceptibility to malignant hyperthermia has been linked to a different part of the same gene, but is more frequently caused by mutations within the ryanodine receptor gene. We report the association of the two disorders in a patient for whom the most frequent mutations for hypokalemic periodic paralysis were not found. This suggests further genetic heterogeneity of this condition, the interest of this case residing in the known coupling between dihydropyridine and ryanodine receptors.