CASCADE TESTING FOR CARRIER STATUS IN CYSTIC-FIBROSIS IN A LARGE FAMILY

The offer to determine carrier status for cystic fibrosis (CF) was mad e to the 230 descendants of a couple who were presumed to carry the DE LTAF508 mutation. ''Cascade testing'' was employed, in which the mutat ion is followed from the oldest generation down. Compliance was over 7 5% and family members were relieved of the anxiety engendered by uncer tainty. In one couple considering having a family, both partners were found to be carriers.