<qa>  What is the genotype that documents the presence of 2 CF-causing mutations?- Participant with clinical diagnosis of CF based on one or more typical clinical features of CF phenotype, in addition to one of the following: a genotype that documents the presence of 2 CF-causing mutation, or a sweat chloride test greater than or equal to 60 millimole per liter mmolL by quantitative pilocarpine iontophoresis on two separate occasions 