Central Core Disease is a rare familial polymyopathy characterized by hypotonia, delay in walking, and muscle weakness. It is associated with abnormalities in the RYR 1 gene. There are cases of MH reported in patients with central core disease. There are also families with CCD that are not MH susceptible. Therefore, extreme caution should be observed in giving anesthetics to these patients.

King Denborough syndrome is a rare myopathy. Several patients with this disorder have been diagnosed as MH susceptible both clinically and by muscle biopsy (18).