Maharasingam M, Ostman-Smith I, Pike MG. Arch Dis Child. 2003;88:61–64
Purpose of the Study.
To examine whether cognitive impairment among patients with DiGeorge syndrome (DGS) is secondary to cardiac pathologic conditions and their treatment or is a feature of the DGS phenotype.
Ten patients with 22q11 deletions who had undergone cardiac repair in infancy, along with 2 control subjects for each patient, matched with respect to gender and age and having the same or similar cardiac defects and normal 22q11, were studied. Children ranged from <1 year to ∼8 years of age at the time of developmental testing.
Patient records were reviewed retrospectively for features of DGS (hypocalcemia and immunodeficiency), operative data such as duration of bypass and postoperative ventilation, and episodes of hypotension or hypoxia and acidosis. Determinations of developmental quotients (DQs) were performed (in an unblinded manner, because DGS is associated with characteristic facial features) by a single investigator, using the Ruth Griffiths Abilities of Infants and Young Children tool. Patient and control groups were compared with multiple analyses of variance.
There were no significant differences between patients and control subjects with respect to age at presentation or surgery or with respect to operative characteristics and complications. Associations with DQs of 22q11 deletions with hypocalcemia and immunodeficiency were highly significant (P = .004-.009); the associations were not independent, because all are linked features of DGS. The DQs for DGS patients (mean: 71; 95% confidence interval: 47–95) were much lower than those for control subjects (mean: 113; 95% confidence interval: 108–118; P = .0001). Perioperative acidosis was strongly associated with lower DQs among children with DGS (P = .005) but not among control subjects.
Abnormal neurodevelopmental outcomes in DGS are not solely the result of cardiac lesions and their surgical repair. Also, DGS may predispose patients to worse neurodevelopmental outcomes after cardiac surgery because of factors intrinsic to the disease, 1 of which appears to be hypocalcemia.
DGS occurs at a rate of ∼1 case per 3000 live births. Previous studies showed developmental delays or cognitive impairment in a subset. This study shows that little is attributable to cardiac complications themselves. However, it suggests that DGS may predispose patients to greater susceptibility to poor neurodevelopmental outcomes after surgery because of associated conditions, such as hypocalcemia.