A Case of "Abnormally Abnormal" Hypoxic Ventilatory Responses: A Novel NPARM PHOX 2B Gene Mutation.

ABSTRACT: Congenital central hypoventilation syndrome (CCHS) is a rare disorder associated with dysregulation of the autonomic ventilatory response to hypoxia and hypercarbia usually caused by polyalanine repeat expansion mutations in the PHOX 2B gene. Non-polyalanine repeat mutations (NPARM) represent approximately 10% of cases, and usually require continuous ventilation during sleep, although our knowledge of disease progression is limited. Here we present a case with a novel NPARM CCHS mutation associated with a premature stop codon for the PHOX 2B protein. Despite the type of the mutation, patient management with supplementary oxygen has been sufficient. Experience from our case may help when counseling parents.