In utero evaluation of velocardiofacial syndrome

Abstract

Velocardiofacial syndrome (VCF) and other 22q11.2 deletion phenotypes can be diagnosed in utero by fluorescence in situ hybridization (FISH) of metaphase or interphase chromosomes from fetal cells obtained at 10–12 weeks by chorionic villus sampling or after 12 weeks by amniocentesis. Definite indications for prenatal testing are a family history of VCF or a 22q11.2 deletion, or ultrasound findings of a conotruncal cardiac defect. Other ultrasound findings reported with, but not specific to the 22q11.2 deletion, are: renal anomaly, polyhydramnios and, in the 10–12 week fetus, increased nuchal translucency. Further, evaluation of the fetus with confirmed or suspected 22q11.2 deletion includes karyotype, comprehensive initial and sequential ultrasounds and echocardiograms including a postnatal echocardiogram, as well as parental testing by FISH. If a deletion is identified, the family should be counseled by a multidisciplinary medical team knowledgeable about the spectrum of clinical features as well as the limitations of prenatal testing for the 22q11.2 deletion. With antenatal diagnosis of VCF or other 22q11.2 deletion syndromes, the parents can make an informed reproductive decision and plan for the current and subsequent pregnancies.