[Strategies in prenatal diagnosis of cystic fibrosis after the introduction of DNA analysis. Initial experience].

The authors describe their experience with the prenatal genetic diagnosis of cystic fibrosis (CF), using DNA analysis in the first trimester of pregnancy in three families with a 25% risk of CF. The authors examined polymorphisms of probes J3.11, met D, met H, KM-19 and XV-2c. All families were fully informative when one or two probes were used. In two families the development of unaffected children--carriers of the gene for CF was proved. In one of these foetuses in the 17th and 21st week false pathological values of microvilillous enzymes were assessed. With regard to this possibility the authors do not recommend to supplement the DNA analysis in the first trimester by biochemical examination of amniotic fluid. The results were confirmed by delivery of unaffected children. In one family DNA analysis revealed the development of an unaffected homozygote, the pregnancy was, however, terminated by a miscarriage. In women with an increased risk of abortion the authors recommend therefore to make the molecular genetic examination during the second trimester from amniotic fluid cells.