Congenital ptosis, scoliosis, and malignant hyperthermia susceptibility in siblings with recessive RYR1 mutations.

Malignant hyperthermia susceptibility is a rare pharmacogenic disorder of skeletal muscle calcium regulation caused by mutations in the skeletal muscle ryanodine receptor 1 gene (RYR1). It is important to identify children who are candidates for ophthalmic surgery who might harbor RYR1 mutations because intraoperative malignant hyperthermia is potentially lethal. We report 2 siblings with congenital ptosis and scoliosis who were considered for ptosis surgery but were found to harbor underlying recessive RYR1 mutations.