Prenatal diagnosis of the 22q11.2 deletion syndrome.

The development of fluorescence in situ hybridization (FISH)- and polymerase chain reaction (PCR)-based assays for the detection of deletions of chromosome 22q11.2 has enabled the medical community to offer couples at risk prenatal diagnostic testing. Current indications for testing include a previous child with a 22q11.2 deletion or DiGeorge/velocardiofacial syndrome, an affected parent with a 22q11.2 deletion, and in utero detection of a conotruncal cardiac defect. Antenatal knowledge of the deletion status provides couples and clinicians with an accurate diagnosis, prognostic information, and recurrence risk, which may assist couples with their reproductive decisions. However, there are limitations to prenatal testing, which should be reviewed prior to testing.