Rapid detection of aneuploidy using FISH in uncultured amniocytes for prenatal diagnosis : 8-year experience

PURPOSE: FISH is suggested as a useful tool for rapid detection of specific aneuploidy in uncultured amniocytes abnormality in interphase nucleus. In this study, we are going to share our experience using FISH in prenatal diagnosis and suggest the criteria for the diagnosis of aneuploidy by analyzing the results of FISH test. METHODS: From January, 1999 to May, 2006, 8,613 tests in amniotic fluids obtained from 7,893 pregnant women were performed by using FISH for prenatal diagnosis of trisomy 21, trisomy 18 and trisomy 13. The indications of chromosome study were a screen positive for Down syndrome or Edwards syndrome in maternal serum marker screening test and an advanced maternal age (> or =35 years old). RESULTS: We have the 8,502 informative results from 8,613 tests (98.7%) which is submitted our criteria and the sensitivity is 98.2%. CONCLUSION: FISH on uncultured amniocytes is a rapid, clinically useful tool for prenatal diagnosis, with informative specimens being highly accurate. But the limitation of FISH is both expensive and labor-intensive.

Application of FISH(Fluorescence In Situ Hybridization) in uncultured chorionic villus cells / 대한산부인과학회잡지

OBJECTIVE: The cytogenetic analysis for earlier detection of fetal chromosome aneuploidies is performed from chorionic villus using either long-term culture or direct chromosome preparation. To analyze the cause of pregnancy loss, we also attempt the cytogenetic study in product of conception(POC) using chorionic villi or fetal tissue. But the failure of analysis often occurs in direct preparation of villus cells and product of conception(POC). We studied to evaluate the clinical usefulness of FISH in uncultured chorionic villus cells of culture-failed cases. METHODS: According to the patient's indication, we performed FISH for chromosome 18, 21, X and Y in chorionic villi as well as POC and compared FISH results with their chromosomal studies. RESULTS: We found one trisomy 18 and one trisomy 21 in Chorionic Villus Sampling and one trisomy 18 and one monosomy X(45, X) in POC. The averages for accuracy of FISH were 83-91% and all cases are represented consistent results with their chromosomal studies. Among them, we could analyze using FISH only in 5 cases of culture failure including one case of monosomy X in POC. CONCLUSION: We could detect aneuploidy with uncultured chorionic villus cells in case of culture failure, using FISH, it may be the potential method to assist the cytogenetic study.