A case of discordant related abnormal karyotypes from chorionic villi and amniocytes

A case of three discordant cell lines in prenatal diagnosis is described, o f which two were abnormal related structural abnormalities of chromosome 11 . One of the abnormal cell lines was seen in all metaphases examined from d irect preparations of chorionic villi, the cultured preparations showing an apparently normal male karyotype; the other abnormal cell line was seen in conjunction with a normal cell line in cultured amniocytes. Prenatal diagn osis offered solely on chorionic villus sampling would have yielded a mista kenly normal result on the basis of established criteria for distinguishing true mosaicism from confined placental mosaicism. Copyright (C) 1999 John Wiley & Sons, Ltd.