MATERNAL UNIPARENTAL DISOMY OF CHROMOSOME-2 AND CONFINED PLACENTAL MOSAICISM FOR TRISOMY-2 IN A FETUS WITH INTRAUTERINE GROWTH RESTRICTION,HYPOSPADIAS, AND OLIGOHYDRAMNIOS

We present a case of maternal uniparental heterodisomy for chromosome 2 (UPD 2) detected after trisomy 2 mosaicism was found on placental bi opsy. This case presented prenatally with severe intrauterine growth r estriction (IUGR) and oligohydramnios. The diploid newborn had hypospa dias and features consistent with oligohydramnios sequence. He died sh ortly after birth of seven pulmonary hypoplasia. The term placenta had high levels of trisomy 2 in both the trophoblast and the stroma, A co mparison of this case with others reported in the literature suggests that the IUGR and oligohydramnios are likely related to placental insu fficiency due to the high levels of trisomy 2 present in the trophobla st of the term placenta and the presence of UPD 2 in the diploid place ntal line. (C) 1997 by John Wiley & Sons, Ltd.