Health Professionals Guide to Newborn Screening

Cystic Fibrosis

Autosomal recessive disorder characterized by pulmonary obstruction and/or exocrine pancreatic dysfunction. The major and most severe genetic mutation causing cystic fibrosis is a three-basepair deletion (F508) in the cystic fibrosis transmembrane regulator (CFTR) gene with a resulting increase in the pancreatic enzyme immunoreactive trypsinogen.

COMMENT: Screening for cystic fibrosis using the two-tiered IRT / DNA approach cannot always distinguish babies who are CF carriers from babies who are affected. Sweat Chloride testing by the CFF-approved quantitative pilocarpine inotophoresis method is recommended for all reported positive screening results, i.e. babies with either one or two mutations detected. For babies with no detectable mutations but with an IRT > 170 ng/mL, the primary care provider should be alert for persistent diarrhea, poor weight gain, chronic cough or respiratory problems. If these signs appear, or if there is a family history of CF, contact should be make with a CF specialist. It is estimated that screening for 25 CF mutations will detect 99% of the CF affected babies.

Information on treatment centers is also available on this site.

For information about other screened disorders, click on the next page button, or follow one of these links:

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