Posted: July 24th, 2017

A 7-month-old infant is brought to the physician’s office because of poor weight gain despite large food intake. He has had two episodes of pneumonia and has frequent bulky stools. He coughs frequently. X-rays of the lungs show increased markings and hyperinflation. Trypsin is absent in a fresh stool sample, and the fat content is increased. Which of the following is the most likely cause of this infant’s disorder?

A 7-month-old infant is brought to the
physician’s office because of poor weight gain
despite large food intake. He has had two
episodes of pneumonia and has frequent bulky
stools. He coughs frequently. X-rays of the lungs
show increased markings and hyperinflation.
Trypsin is absent in a fresh stool sample, and the
fat content is increased. Which of the following
is the most likely cause of this infant’s disorder?
(A) Autoimmune disorder
(B) Defective ion transport at epithelial
surfaces
(C) Disaccharidase deficiency
(D) Inability to synthesize apolipoprotein B
(E) Villous atrophy of the jejunum