Prenatal diagnosis for the cystic fibrosis mutation 1717-1, G-->A using arms.

A family carrying two cystic fibrosis mutations, delta F508 and 1717-1, G-->A, requested prenatal diagnosis. In order to eliminate the need for labelling of allele-specific oligonucleotides and to simplify the analysis, 1717-1, G-->A was detected using an ARMS (amplification refractory mutation system) method (Newton et al., 1989). Fetal DNA was obtained by chorionic villus sampling (CVS) and the ARMS technique was used to exclude the 1717-1, G-->A mutation. The fetus was found to be heterozygous for the delta F508 mutation. ARMS is a simple, quick, non-radioactive method suitable for detecting DNA mutations in various clinical situations.