22q11 deletions in patients with conotruncal heart defects

Objective: To ascertain the frequency of 22q11 deletions in a representative population of conotruncal heart defects (CTD) and determine which children are at risk of having a deletion. Methodology: A clinical and laboratory evaluation of 90 children with CTD, including isolated and syndromic cases. Results: Fifteen children (17%) were shown to have 22q11 deletions by fluorescence in situ hybridization (FISH) studies with the Oncor probe N25. Varying degrees of developmental delay/learning disabilities and facial dysmorphism were common in these children. None of the isolated cases without dysmorphism had a deletion. Conclusion: 22q11 deletions are a significant cause of a specific form of congenital heart disease, CTD. It is important to have a high index of suspicion of the 22q11 deletion disorders in children with CTD and other extracardiac manifestations so that the diagnosis can be made early and appropriate interventions implemented.