On the parental origin of the X's in a prenatally diagnosed 49,XXXXX syndrome.

A 49,XXXXX fetus was detected in amniotic fluid cell cultures from a 39-year-old mother. On ultrasonography, growth retardation and bilateral radioulnar synostosis were found. Additional clinical manifestations were mild facial anomalies and hypoplastic ovaries depleted of oocytes. Molecular analysis showed that this aneuploidy arose by successive maternal non-disjunction.