TWO SUCCESSFUL PREGNANCIES IN A WOMAN WITH MOSAIC FORM OF DOWN SYNDROME

We present two successful pregnancies in a patient with mosaic trisomy 21, diagnosed shortly after birth with a proportion of 20% trisomic cells. Amniocentesis was performed in both pregnancies and normal female karyotypes were obtained by classical cytogenetic analysis.  Fluorescence in situ hybridization (FISH) showed trisomy 21 in 10% of patient’s peripheral blood cells and confirmed a normal fetal karyotype in amniotic fluid cell cultures from both pregnancies. Phenotypically normal female infants were delivered at 36 and 40 weeks gestation, respectively. Postnatal follow-up was uneventful. Our cases emphasize the importance of FISH as a very useful method for fast screening of large number of fetal cells within a short time for proper prenatal diagnosis.