Vasomotor instability in neonates with chromosome 22q11 deletion syndrome

Abstract

Approximately 70% of individuals with chromosome 22q11 deletion syndrome (22q11DS) have congenital heart defects. A host of other vascular problems in these patients, such as tortuous carotid arteries, Raynaud's phenomenon, unexplained hypotension, hypertension, and hypothermia, raise the possibility that there may be abnormal autonomic regulation of the vascular system. So far, however, there has been no formal report of autonomic dysfunction in patients with 22q11 deletion. We present two infants with 22q11DS, who had profound hypotension after uncomplicated surgeries for congenital heart disease. The hypotension was not responsive to vasopressor treatment (and extracorporeal membrane oxygenation in one infant) and resulted in death, due to multiorgan system failure. Obvious causes, such as poor cardiac contractility, prolonged circulatory arrest, neurological abnormality, sepsis and blood loss were excluded. On autopsy, no abnormalities were found that could explain the hypotension. We hypothesize that these infants died of severe hypotension due to abnormal vascular tone and that this is a variable feature in individuals with 22q11 deletion. The autonomic nervous system, which is responsible for the regulation of vasomotor tone, may be variably affected in 22q11DS. This could have implications for the surgical management of patients with 22q11DS. Further studies on this topic would establish or refute the association between 22q11DS and dysautonomia.

Persistent low thymic activity and non-cardiac mortality in children with chromosome 22q11·2 microdeletion and partial DiGeorge syndrome

“…Standard T cell enumeration of overall CD4 T cells, lymphocyte proliferation tests towards mitogens or detection of humoral immune responses failed to identify these patients in time. We, as others, believe that loss of immune surveillance because of persistent low thymic output, low TRECs and concomitant compromised T cell receptor diversity is the most likely explanation for such complications in pDGS patients, although nonimmunological morphological factors may play a role [5,22,26,27,[33][34][35][36][37][38].…”

Premature death in adults with 22q11.2 deletion syndrome

“…The average age at natural death is older and mortality rates much lower32 than we observed in 22q11.2DS schizophrenia (44.8 years; 16%, respectively), however. Impaired autonomic activity has been reported postoperatively in two children with 22q11.2DS34 and, as for the general population,27 – 29 should be considered as another possible mechanism predisposing to sudden death.…”

Cardiac defects and results of cardiac surgery in 22q11.2 deletion syndrome

“…A fair amount of vasomotor instability should also be taken into account [Shashi et al, 2003], as well as the potential for bronchospasm [Ackerman et al, 2001], or the association with laryngeal web [McElhinney et al, 2002] and airway bleeding [Carotti et al, 2003c].…”