1. This complex of symptoms appears to be congenital, familial, and hereditary. It is apparently transmitted by a dominant gene, probably on chromosome 5. 2. Hypertonicity with rigidity of all voluntary muscles usually presents at birth. 3. Feeding problems are due to dysphagia or laryngospasm associated with aspiration and dyspnea. 4. Respiratory problems are characterized by apneic episodes due to muscle spasm. 5. Prolonged episodes of muscular rigidity secondary to sudden stimuli result in frequent falls, characteristically en bloc, like a statue. 6. Continuous electromyographic activity even at rest (with absence of fasciculations) improves after intravenous diazepam.