Late-onset, insidious course and invasive treatment of congenital central hypoventilation syndrome in a case with the Phox2B mutation: case report

Abstract

Congenital central hypoventilation syndrome (CCHS) is a rare disorder of respiratory control characterized by ventilatory impairment that results in arterial hypoxemia. This condition is worse during sleep and occurs in patients with normal mechanical properties of the lung. It is diagnosed in the absence of primary neuromuscular disease, identifiable brainstem lesions, and other sleep disturbances or substance use [1]. Amiel et al. [2] identified a mutation in the Phox2B gene associated with CCHS, characterized by five to nine alanine expansions within a 20-residue polyalanine region in exon 3 of the Phox2B gene. Several reports confirmed the findings of Amiel et al., supporting the view that this gene is a master switch for the development of the autonomic nervous system network linked to respiratory control [3–6]. Transgenic animals carrying the human Phox2B mutation develop a similar phenotype and lack glutamatergic neurons located in the parafacial region in the brainstem, which are involved in breathing control [7]. Although patients typically present with CCHS as newborns and rarely in later infancy, there have been reports of patients presenting with CCHS in adulthood. In cases of late-onset CCHS, most patients report having had some symptoms since childhood, and they have parents with a history of CCHS. Symptoms of right-sided heart failure are generally observed at the time of diagnosis, and nocturnal noninvasive ventilation is frequently indicated [8–15]. L. R. A. Bittencourt (*) :M. Pedrazzoli : F. Yagihara : G. P. Luz : S. Garbuio :G. A. Moreira : S. Tufik Disciplina de Medicina e Biologia do Sono, Departamento de Psicobiologia, Universidade Federal de Sao Paulo, Rua Napoleao de Barros, 925, 04024-002 Sao Paulo, Sao Paulo, Brazil e-mail: lia@psicobio.epm.br