A 3-year-old boy is brought to the office with 5 days of productive cough and fever. Examination shows a tachypneic, ill-appearing child with rales over the right lower lung. Chest x-ray reveals right lower lobe pneumonia. The boy is admitted to the hospital for intravenous antibiotics. Review of his medical history shows 4 prior pneumonias, and his weight is at the third percentile. Further testing demonstrates high sweat chloride content, and genetic sequencing shows a mutation in a transmembrane protein. Which of the following best describes the dysfunctional transmembrane protein causing this patient's disease?

Question

A 3-year-old boy is brought to the office with 5 days of productive cough and fever.  Examination shows a tachypneic, ill-appearing child with rales over the right lower lung.  Chest x-ray reveals right lower lobe pneumonia.  The boy is admitted to the hospital for intravenous antibiotics.  Review of his medical history shows 4 prior pneumonias, and his weight is at the third percentile.  Further testing demonstrates high sweat chloride content, and genetic sequencing shows a mutation in a transmembrane protein.  Which of the following best describes the dysfunctional transmembrane protein causing this patient's disease?

Quizplus · Accepted Answer

Eductional Objective: Cystic fibrosis is an autosomal recessive disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene.  The CFTR protein is a transmembrane ATP-gated chloride channel.  Defects in CFTR result in thick, plugging mucous and elevated sodium and chloride levels in sweat.

A 3-Year-Old Boy Is Brought to the Office with 5