* 1. A 15 year old white female presents with persistent cough and recurrent sinusitis. An oropharyngeal culture demonstrates the presence of Pseudomonas aeruginosa.  Which of the following statements is correct?

* 2. In the 15 year old female described above, the results of the sweat chloride are 51 and 54 mmol/L. Which of the following statements best describes the correct interpretation of this result?

* 3. A 2 week old infant has a positive CF newborn screening test showing one copy of F508del mutation and one copy of G551D mutation.  Sweat chloride values of 42 and 39 mmol/L are obtained using bilateral sampling of adequate volumes. It is most likely that this infant:

* 4. A newborn girl at age 3 weeks had a positive CF newborn screening test.  Her mother was found to carry a disease-causing CFTR mutation and her father was found to have CFTR variant of unknown significance. Amniocentesis revealed that the infant has both the mutation and the variant.  Her sweat chloride values are 9 and 10 mmol/L.  Appropriate management of this infant includes:

* 5. The infant in the prior scenario had a repeat sweat chloride of 31 mmol/L at two months of age.  She is next seen for a follow-up visit at the CF clinic at one year of age and is noted to have excellent growth and no respiratory illnesses or symptoms.  She has a pharyngeal culture performed which grows Pseudomonas aeruginosa. 

The best immediate management of this child includes:

* 6. A 4 week old infant is referred to the CF Center because of a positive NBS.  Mutation analysis using a panel of 23 CFTR mutations from his CF NBS test showed 1 copy of F508del on one allele and no identified mutations on the other allele.  He undergoes sweat testing, and his sweat chloride concentrations were 31and 35 mmol/L.  Of the following, which tentative conclusion and course of action are best?

* 7. In the case of the 4 week old infant described above with positive NBS and one F508del mutation, CF treatment should be initiated while efforts to establish a diagnosis of CF are pursued further.

* 8. A 4 week old infant is referred to the CF Center because of an initially high IRT level that is confirmed with repeat testing at 2 weeks of age in a state that uses the IRT/IRT protocol.  He then undergoes bilateral sweat testing, and his sweat chloride concentrations are 31 and 35 mmol/L. Which one of the following statements is true? 

* 9. A 4 week-old infant with an ultrahigh IRT level (>300 ng/ml) has one F508del mutation and the 23 CFTR mutation testing was otherwise negative, i.e., a single CF-causing allele was detected. What is your interpretation?  

* 10. When performing bilateral QPIT with the Gibson-Cooke method on a 3 week-old baby, resulting in 65 mg from the left arm and 75 mg from the right arm, and chloride values considered reliable by your clinical lab, which of the following procedures is correct?

* 11.  Which of the following statements are most likely to be the etiology of a 20 mmol/L false negative sweat chloride result in a full term 3 week-old infant with a high IRT level and two CF-causing CFTR mutations?

* 12. An adolescent 15 y/o female diagnosed with asthma since 5 years of age develops recurrent pancreatitis, shows a sweat chloride of 49 mmol/L, and a genotype of F508del/no mutation found in a DNA analysis of 23 CFTR mutations. You are concerned that she has CF.  What is the next best step or steps for evaluation?

* 13. Causes of a false positive sweat test include all but one of the following.