Prenatal diagnosis by minisatellite analysis in Italian families with phenylketonuria.

[classical phenylketonuria]

A polymorphic short tandem repeat (STR ) in intron 3 (Goltsov et al ., 1993 ) and a variable number of tandem repeats (Hind III -VNTR ) flanked by two constant Hind III sites (Golstov et al ., 1992 ) have been recently identified in the human phenylalanine hydroxylase (PAH ) gene . These polymorphisms are easily detected by the polymerase chain reaction (PCR ) and gel electrophoresis . We report on the use of these two novel polymorphisms in three Italian families with pregnancies at risk for classical phenylketonuria (PKU ). A carrier status for PKU was ascertained in two fetuses ; the third family refused prenatal diagnosis , although informativeness was shown to be complete .