Objective: To evaluate the feasibility of using fluorescence in situ hybridization(FISH) for the detection of a few common chromosome aneuploidies on interphase nuclei of uncultured amniotic fluid cells.
Methods: Amniotic fluid samples were taken from 55 women at 16-32 weeks of pregnancy; interphase FISH was performed for diagnosing Down syndrome and aneuploidies of other four chromosomes 13, 18, X and Y. Then the karyotypes from standard cytogenetic analysis after percutaneous umbilical blood sampling(PUBS) were compared to the FISH results.
Results: Each of the 55 uncultured amniotic fluid samples tested with FISH was enumerated 200 nuclei. Fifty-three samples were normal. Two samples were found to have trisomy 21(one is a case of standard trisomy 21 with three signals in all 200 nuclei, the other is a mosaic trisomy 21).
Conclusion: Interphase FISH analysis of uncultured amniotic fluid cells is a rapid, accurate and very sensitive method. It could be used in the prenatal cytogenetic laboratory.