Congenital central hypoventilation syndrome (CCHS), a rare disorder typically presenting in the newborn period, results from PHOX2B polyalanine repeat mutations in over 90% of cases. It is characterized by alveolar hypoventilation, symptoms of autonomic nervous system dysregulation, and in a subset of cases Hirschsprung’s disease and later tumors of neural crest origin. We describe a preterm infant with severe phenotype of CCHS and hyperinsulinism. A novel de novo heterozygote missence mutation (Gly68Cys) in the PHOX2B gene could be identified. Based on the observation of three patients presenting with the combination of congenital hyperinsulinism and CCHS, hyperinsulinism might represent an additional clinical feature of CCHS.