Late-onset hypoventilation without PHOX2B mutation or hypothalamic abnormalities.

Most children with idiopathic central hypoventilation have symptoms at birth or shortly thereafter and have mutations of the PHOX2B gene. Those whose symptoms appear later usually have obesity and hypothalamic abnormalities. We describe a case of a boy who presented at 5 years of age with severe idiopathic central hypoventilation, but no obesity or hypothalamic abnormalities, and who tested negative for mutation of the PHOX2B gene. This case illustrates the heterogeneity of childhood idiopathic central hypoventilation syndromes and indicates the multifactorial etiology of these syndromes.