PRENATAL-DIAGNOSIS OF TRISOMY-9 - CYTOGENETIC, FISH, AND DNA STUDIES

A cytogenetic survey and follow-up studies were performed in eight cas es of full, mosaic, and pseudomosaic trisomy 9 prenatally diagnosed am ong 36 213 prenatal samples in our department between August 1970 and July 1996. Besides conventional chromosome analysis, interphase fluore scent in situ hybridization (FISH) was employed. FISH turned out to be a rapid and accurate method for verification of trisomy cell lines an d could provide additional information to the prenatal cytogenetic res ults. FISH also enables the study of uncultured specimens of amniotic fluid, not accessible for traditional cytogenetic analysis. In three c ases, retrospective DNA analysis showed the supernumerary chromosome 9 to be of maternal origin. The disomic cell lines in both mosaic triso my 9 cases showed maternal uniparental disomy. (C) 1997 by John Wiley & Sons, Ltd.