Animals with a knockout of all three genes died: the loss of function of Scn1A (NaV1.1) resulted in seizures; the loss of function of Scn2A (NaV1.2) resulted in respiratory failure and death in neonatal mice; and the loss of function of Scn8A (NaV1.6) resulted in the failure of neuromuscular junctions and hind limb paralysis, culminating in death at 3 weeks of age. This evidence concerns the gene SCN8A and respiratory failure.