Renal abnormalities on obstetric ultrasound as a presentation of DiGeorge syndrome.

We describe three pregnancies that presented with renal anomalies on obstetric ultrasound as the main abnormality and were subsequently found to have interstitial deletions within chromosome 22q11. A cardiac defect, double-outlet right ventricle, was also seen in the first case. Amnio infusion was refused in the second pregnancy and the perimembranous ventricular septal defect was not identified prior to termination. In the third case, there was no cardiac defect. The genitourinary abnormalities were a right hydroureter and hydronephrosis with a ureterocele bulging into the bladder lumen, bilateral multicystic kidneys with associated oligohydramnios, and a left multicystic kidney with right renal agenesis and associated oligohydramnios. Absence of thymus at autopsy in all three cases led to fluorescent in situ hybridization studies looking for the submicroscopic deletion of chromosome 22q11 associated with DiGeorge syndrome.