[Molecular biology and mucoviscidosis. Brest experience in 1987].

The gene for cystic fibrosis is located on the long arm of chromosome 7 at 7q31. The close linkage between the disease locus and several DNA markers allowed a study of the DNA restriction polymorphism pattern in 30 Breton families. The frequency of the haplotypes indicated by the probes pJ 3.11, met H and met D was established reaching a 66.6% informativity for the families studies. The complete informativity of a family allows for detection of heterozygous brothers and sisters, uncles and aunts and for antenatal screening on trophoblast biopsies in case of further pregnancies.