Cyanotic episodes in a male child with fragile X syndrome.

A 9-year-old male with a diagnosis of fragile X syndrome (FXS) was evaluated for cyanotic episodes of unknown etiology. Clinical observation revealed frequent episodes of hyperventilation lasting several minutes, only while the patient was awake. This was followed by apnea associated with cyanosis and oxygen desaturation. Polysomnogram confirmed episodic central apnea temporally associated with hypocapnia, only during the awake state. Extensive evaluation failed to reveal other neurological, cardiac, gastrointestinal, or pulmonary etiologies for the events. The clinical observations and investigations allowed us to conclude that the patient's cyanotic episodes were caused by primary behavioral hyperventilation in the awake state. Similar behaviors have been reported in children with a variety of diagnoses but to our knowledge have not been previously reported in children with FXS. Treatment for this unusual behavior in FXS consists of reassurance and behavior modification to decrease the frequency and severity of the cyanotic episodes.