Prenatal diagnosis of 46,XY/46,XX mosaicism: A case report†

We report on the prenatal diagnosis of a fetus with 46,XY and 46,XX cell lines with a normal male phenotype. Cytogenetic and molecular studies ruled out the possibility of maternal cell contamination and showed that all the X chromosomes present in both fetal cell lines were derived from a single maternal X chromosome. This suggests 46,XY/46,XX mosaicism. Am. J. Med. Genet. 84:12–14, 1999. © 1999 Wiley-Liss, Inc.