[1] Univ Washington, Dept Med, Seattle, WA 98195 USA
[2] Univ Washington, Dept Pediat, Seattle, WA 98195 USA
[3] Seattle Children s Res Inst, CF Therapeut Dev Network Coordinating Ctr, Seattle, WA 98101 USA
[4] Case Western Reserve Univ, Sch Med, Dept Pediat, Cleveland, OH USA