PHOX2B and autonomic nervous system disorder: Therefore, CCHS, ALTE, and SIDS might be members of the same group of respiratory and autonomic disorders of infancy and, along an imaginary severity line, starting from the “chronic” CCHS to the fatal SIDS, they might belong to a same sudden perinatal disorder spectrum (Figure 4), with PHOX2B variants playing a causative role in CCHS and predisposing to the two other disorders.