First-trimester prenatal diagnosis of cystic fibrosis using the polymerase chain reaction: report of eight cases.

Eight pregnancies at risk for cystic fibrosis have been monitored by first-trimester prenatal diagnosis with DNA amplification analysis. The polymerase chain reaction (PCR) was used in all cases to amplify the region detected by KM19. In two cases, the region detected by CS.7, another DNA probe tightly linked to the CF locus, was also examined. The results of the PCR determinations were confirmed using the Southern blotting procedure, by segregation analysis of restriction fragment length polymorphisms (RFLPs) relative to XV-2c, J3.11, metH, metD, and KM19 probes.