[1] Univ Hosp Santa Maria, Dept Paediat, Cyst Fibrosis Ctr, Parede, Portugal
[2] Univ N Carolina, Sch Med, Cyst Fibrosis Pulm Res & Treatment Ctr, Chapel Hill, NC USA
[3] Univ Lisbon, Fac Sci, Dept Chem & Biochem, P-1699 Lisbon, Portugal
[4] Natl Inst Hlth, Ctr Human Genet, Lisbon, Portugal