What does enteropeptidase deficiency lead to in infants?

• A. Inability to absorb vitamin B12
• B. Inability to convert trypsinogen to trypsin
• C. Inability to produce intrinsic factor
• D. Inability to synthesize bile acids

Answer: (B)

Enteropeptidase, also known as enterokinase, is an enzyme produced in the intestinal mucosa that plays a crucial role in digestion by activating trypsinogen, a precursor of trypsin. Trypsin is essential for the activation of other digestive enzymes and for the proper digestion of proteins.

When there is a deficiency of enteropeptidase in infants, the conversion of trypsinogen to trypsin does not occur effectively. As a result, the subsequent cascade of activation needed for other pancreatic enzymes (like chymotrypsin and carboxypeptidase) is also impaired. This leads to a malabsorption syndrome because proteins cannot be adequately digested into their absorbable units (amino acids and small peptides).

Consequently, the infant would display symptoms such as failure to thrive, diarrhea, and nutritional deficiencies due to the inadequate digestion and absorption of proteins. Therefore, the inability to convert trypsinogen to trypsin is the main consequence of enteropeptidase deficiency in infants, leading to significant digestive issues.