22q11.2 deletion syndrome in patients admitted to a cardiac pediatric intensive care unit in Brazil.

The 22q11.2 deletion syndrome (22q11DS) is one of the most recognizable causes of congenital heart defects (CHDs), but the frequency varies in non-selected populations. The purpose of this study was to determine the incidence and clinical features of patients with CHD and 22q11DS admitted to a pediatric cardiology intensive care unit in Brazil. In a prospective study, we evaluated a consecutive series of 207 patients with a CHD following a clinical protocol and cytogenetic analysis by high resolution karyotype and fluorescent in situ hybridization (FISH). 22q11DS was identified in four patients (2%), a frequency similar to studies that evaluated subjects with major CHDs in other countries. Despite this similarity, we believe that the low rate of prenatal identification of CHDs and the limited access of these patients to appropriate diagnosis and care, which occur in our region, could have had an influence on this frequency. It is possible that 22q11DS patients with a severe CHD could have died before having a chance to access a tertiary hospital, leading to an underestimate of its frequency. (c) 2008 Wiley-Liss, Inc.