PRENATAL-DIAGNOSIS OF TRISOMY-9 MOSAICISM - 2 NEW CASES

We present two prenatal cases of trisomy 9 mosaicism, both of which pr esented intrauterine growth retardation (IUGR) and other abnormal ultr asound findings. In case A, mosaicism was found in amniotic fluid cell cultures, of which 65 per cent were trisomic cells, on average. In ca se B, trisomic cells were present in amniotic fluid cell cultures (12 per cent) but none were found in fetal cord blood. After autopsy, cyto genetic findings were confirmed in different tissue cultures. It is co ncluded that echographic indicators are a very useful tool for a corre ct prenatal diagnostic interpretation of trisomy 9. Suspected trisomy 9 mosaicism always requires further investigation and fetal cord blood cytogenetic analysis may not be considered as providing an accurate d iagnosis of fetal trisomy 9.