In Reply.—We agree with Drs Rutledge and Haas that Turner's syndrome has to be ruled out in a patient with evidence of hygroma. We raised the possibility of Turner's syndrome in our report and recommended amniocentesis because of the increase of α-fetoprotein in the fluid of fetuses with Turner's syndrome, though some believe that this is due to obtaining fluid from the cervical sac rather than from amniotic fluid.
As far as genetics is concerned, a majority of patients with Turner's syndrome are 45,X. However, 20% to 30% have various types of mosaicism including X/XX, X/XY, and X/XX/XY, or structurally altered chromosomes, such as an isochromosome X, ring X, or partial deletion of the X chromosome. No chromosomal analysis of amniotic fluid was done on our patient. A chromosomal study was attempted in the stillborn infant, but due to maceration of the fetal tissue the study was not