Columbia subject headings:
Cystic fibrosis.
Medical screening.
Harvard subject headings:
Cystic fibrosis gene--Research--United States.
Cystic fibrosis--Diagnosis
Recombinant DNA--Research--United States.
Princeton subject headings:
Cystic fibrosis gene--Research--United States.
Cystic fibrosis--Diagnosis.
Recombinant DNA--Research--United States.