Prenatal Diagnosis of Digeorge Syndrome

Abstract

Velocardiofacial syndrome, conotruncal congenital heart disease and DiGeorge syndrome present different aspects of the same clinical situation, but congenital heart disease is common to them all [1]. Other defects found in these syndromes include abnormal facies, thymic hypoplasia, cleft palate, and hypocalcemia. A deletion at chromosome 22q11 is the second most common chromosomal defect detected in patients with congenital heart disease. Although familial inheritance occurs, most cases are sporadic [2]. A patient aged 29 years, gravida 2, para 1, presented to our outpatient clinic with an initial diagnosis of polyhydramnios at the 33 rd week of gestation. Her medical history revealed that her first delivery was at term by cesarean section, but the baby died in infancy of cyanotic heart disease, diffuse bronchopulmonary disease, and infection. Postmortem genetic investigation revealed that the neonate had a 22q11 deletion, with associated cardiovascular anomalies. The parents were genetically normal. Obstetric examination determined that the patient was at 33 weeks of gestation, and fetal biometric measurements suggested a gestational age of 31–32 weeks. The amniotic index was 18 cm and mild polyhydramnios was detected. Systematic ultrasonographic investigation revealed a ventricular septal defect, a secundum-type atrial septal defect, pulmonary atresia, and an anomaly of the overriding aorta. These findings were interpreted as components of tetralogy of Fallot (TOF). The patient had not attended the hospital for prenatal screening during her second trimester. Cordocentesis was performed for prenatal diagnosis. The cytogenetic analysis was evaluated as normal, but considering the clinical findings and the patient’s prior history, locus-specific fluorescence in situ hybridization (FISH) was planned to detect possible DiGeorge syndrome. A Tuple1-Hira