We report a prenatal case of double aneuploidy (consisting of chromosome 7 and X) with the features of Potter sequence. Of the stillborn fetus, skin fibroblast cultures were performed and fluorescence in situ hybridization (FISH) technique was also used for further investigation. On physical examination; the fetus was found to have malformed ears, micrognatia, hypertelorism, abnormal extremities, rocker-bottom feet and abnormal external genitalia and polycystic right kidney was seen after an extensive autopsy. As amniocentesis and cordocentesis materials revealed X chromosome mosaicism, trisomy 7 was detected in the skin fibroblast culture of the ex fetus and karyotype evaluated as composite; 46 similar to 47,X,+7,-X[cp18]. FISH results confirmed the double aneuploidy and also revealed XX and XXXX cell lines. Comparison with the previously reported cases of trisomy 7 with Potter syndrome suggests a possible link (if not coincidental) between trisomy 7 and Potter syndrome in our case. This is the first reported case of double aneuploidy involving trisomy 7 with the features of Potter syndrome. (c) 2005 Elsevier SAS. All rights reserved.