Central core disease of muscle
One of the conditions that produces 'floppy baby' syndrome.
CCD causes hypotonia (floppiness) in the newborn baby, slowly progressive muscle weakness, and muscle cramps after exercise.
Muscle biopsy shows a key diagnostic finding (absent mitochondria in the center of many type I muscle fibers).
CCD is inherited as a dominant trait.
The CCD gene is on chromosome 19 (and involves ryanodine receptor-1).