A 3-year-old Caucasian boy is brought to the clinic for a chronic productive
cough not responding to antibiotics given recently. He has no fever or sick
contacts. His medical history is significant for abdominal distention, failure to
pass stool, and emesis as an infant. He continues to have bulky, foul-smelling
stools. No diarrhea is present. He has several relatives with chronic lung and
“stomach” problems, and some have even died at a young age. The examina-
tion reveals an ill appearing, slender male in moderate distress. The lung exam
reveals poor air movement in the base of lungs bilateral and coarse rhonchi
throughout both lung fields. A chloride sweat test was performed and was
positive, indicating cystic fibrosis (CF).
What is the mechanism of the disease?
How might gel electrophoresis assist in making the diagnosis?