A 3-year-old Caucasian boy is brought to the clinic for achronic productive cough not responding to antibiotics givenrecently. He has no fever or sick contacts. His medical history issignificant for abdominal distention, failure to pass stool, andemesis as an infant. He continues to have bulky,foul-smellingstools. No diarrhea is present. He has several relatives withchronic lung and “stomach” problems, and some have even died at ayoung age. The examination reveals an ill appearing, slender malein moderate distress. The lung physical reveals poor air movementin the base of lungs bilateral and coarse rhonchi throughout bothlung fields. A chloride sweat test was performed and was positive,indicating cystic fibrosis (CF). What is the mechanism of thedisease? How might gel electrophoresis assist in making thediagnosis?
