CCD (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).