Prenatal diagnosis of purine nucleoside phosphorylase deficiency in the first and second trimesters of pregnancy.

Prenatal diagnosis was performed in two successive pregnancies of a mother with a previous child with purine nucleoside phosphorylase (PNP) deficiency. In one pregnancy, an affected fetus was diagnosed in the 18th week of gestation after the demonstration of PNP deficiency in cultured amniotic fluid cells. Also an abnormal purine nucleoside profile was found in the amniotic fluid. The diagnosis of an affected fetus was confirmed by the analysis of cultured fetal skin fibroblasts and placental villi. The complete deficiency of PNP activity in placental villi confirms that the prenatal diagnosis of this disorder is possible by the direct investigation of chorionic villi. In the subsequent pregnancy, a heterozygous fetus was predicted in the tenth week of pregnancy by using chorionic villi.