Screening for 22q11 deletion syndrome among patients with congenital heart defects.

The 22q11 deletion syndrome (22q11DS), or velocardiofacial/DiGeorge syndrome, is considered to be the second most known genetic cause of congenital heart disease (CHD).1 Our aim was to evaluate the effectiveness of different screening methods for 22q11DS in patients with CHD. Our study evaluated a consecutive sample of patients with CHD hospitalized for the first time in a pediatric and cardiac intensive care unit of a referral hospital in southern Brazil. All of them underwent the examination through fluorescent in situ hybridization for 22q11DS. These patients were part of the study by Rosa et al.2 CHDs were classified by a cardiologist as conotruncal or non-conotruncal. We excluded patients with other chromosomal abnormalities. Three different approaches composed the screening: (1) Testing suggested by Tobias et al.3 The clinical findings are divided into three categories: A) conotruncal CHD; B) abnormalities common in 22q11DS, such as hypocalcemia and non-conotruncal CHD; and C) abnormalities less common in 22q11DS, such as short stature and hypotonia. Patients that have an alteration in group A, two findings in group B, or one finding in group B plus one in group C are tested; (2) Testing suggested by the American Heart Association (AHA) Congenital Cardiac Defects Committee,4 which consists of testing all newborns/infants with interrupted aortic arch (IAA), truncus arteriosus (TA), tetralogy of Fallot (TOF), ventricular septal defect (VSD) (perimembranous conoseptal hypoplasia or malalignment) with aortic arch anomaly (AAA), AAA alone and discontinuous branch pulmonary arteries. The screening also includes any newborn/infant/child with CHD associated with another feature of 22q11DS (such as hypocalcemia, facial dysmorphia and palate abnormality); newborns/infants with VSD, and any child/ adolescent/adult with TOF, TA, IAA, VSD or AAA who has one other feature of 22q11DS; (3) Testing performed at some centers,5 where only patients with conotruncal heart defects are tested.