Prenatal diagnosis of 22q11.2 deletion syndrome in twin pregnancy: a case report.

Chromosome 22q11.2 deletion syndrome is a common genetic disorder, also known as DiGeorge syndrome. It occurs in approximately 1:4,000 births, and the incidence is increasing due to affected parents bearing their own affected children. We report the prenatal diagnosis of 22q11.2 deletion syndrome by fluorescence in situ hybridization in twin fetuses having tetralogy of Fallot with absent pulmonary valve.