[2] CCD is usually diagnosed in infancy or childhood, but some patients remain asymptomatic until adulthood to middle age.

Most cases have demonstrable mutations in the ryanodine receptor type 1 (RYR1) gene,[1] which are often de novo (newly developed).

People with CCD are at increased risk for developing malignant hyperthermia (MH) when receiving general anesthesia.

[2] The diagnosis is made based on the combination of typical symptoms and the appearance on biopsy (tissue sample) from muscle.

The name derives from the typical appearance of the biopsy on light microscopy, where the muscle cells have cores that are devoid of mitochondria and specific enzymes.