Congenital central hypoventilation syndrome (CCHS) is a rare disease characterized by abnormal autonomic control of breathing resulting in hypoventilation. We report an infant girl with CCHS who presented with central sleep apnea, which was fi rst demonstrated by polysomnography when the infant was 5 months old. She was heterozygous for the novel 590delG mutation of PHOX2B, which is classifi ed as a non-polyalanine repeat mutation (NPARM). This mutation is considered to be associated with a relatively mild phenotype. 2-4 Subsequently, Weese-Mayer and colleagues identifi ed mutations in exon 3 of the PHOX2B gene in all patients with the CCHS phenotype.5 Currently, identifi cation of a PHOX2B mutation is required to confi rm the diagnosis of CCHS. CCHS patients characteristically demonstrate alveolar hypoventilation with diminutive tidal volumes and monotonous respiratory rates during sleep, and in severe cases, also during wakefulness.5 Affected individuals have diffuse autonomic nervous system dysregulation (ANSD), with anatomical manifestations such as the risk of tumor development. Mcconville et al. identifi ed two PHOX2B mutations (600delC, a frameshift mutation and G197D, a missense mutation) as a rare cause of non-syndromic neuroblastoma, which indicates that the underlying PHOX2B mutational mechanism infl uences the risk of tumor and suggests that the position of missense mutations may infl uence the resulting phenotype. We report an infant with CCHS who presented with central sleep apnea, which was fi rst demonstrated by polysomnography (PSG) when the infant was 5 months old. She was heterozygous for the novel 590delG mutation of PHOX2B.
REPORT OF CASEThe patient was a 5-month-old girl delivered by Cesarean section performed for obstructed labor at 40 weeks of gestation without any other complication during pregnancy and delivery. The Apgar scores were 8 at 1 min and 9 at 5 min. She was born to healthy parents without consanguinity: a 33-year-old father and a 23-year-old mother. No relatives of either parent suffered from sleep disorders. Three of the infant's grandparents had undergone surgery under anesthesia without any problems of respiratory management. Neither the parents nor the siblings showed any signs of Hirschsprung disease, tumors of neural crest origin, or other symptoms suggestive of ANSD.The patient was admitted to NICU because of frequent episodes of respiratory arrest for a few seconds at the onset of sleep on the day of birth. There were no rales or heart murmurs. The muscle tone was good. Venous blood gas analysis revealed a PvCO 2 of 32.7 mm Hg in room air. There were no abnormalities on x-ray examination of the chest/abdomen, examination of the cerebrospinal fl uid, or ultrasound examination of the brain and heart. The patient was discharged from the NICU one month after birth under home oxygen therapy; supplemental oxygen by nasal cannula (2 L/m) during sleep with SpO 2 monitoring was prescribed at discharge. She was brought to the hospital in which she was born at 5 months of age wi...