Prenatal diagnosis of 22q11.2 deletion when ultrasound examination reveals a heart defect

Purpose: The incidence of 22q11.2 deletion syndrome is approximately 1 in 5,000 births, and accounts for 5-30% of all heart defects, making it one of the more common genetic conditions in the population. Methods: We employed fluorescence in situ hybridization (FISH) to study the incidence of 22q11.2 deletions in fetuses with cardiac anomalies detected on ultrasound examination. Results: Of 64 cases, 18 had visible chromosome anomalies. FISH testing for 22q11.2 deletion was performed on the remaining 46 cases, and five exhibited a 22q11.2 deletion. Three of the five had de novo deletions, one was maternally inherited, and one family declined testing. Conclusion: FISH analysis for 22q11.2 deletion should be performed on all fetuses with cardiac defects (excluding hypoplastic left heart and echogenic focus) and a normal G-banded karyotype.