Isolated Trypsin and Chymotrypsin Deficiency in a 2 Year Old Male

Abstract

Purpose: Isolated trypsin and chymotrypsin deficiency is a very rare cause of poor growth and malabsorption. Pancreatic insufficiency is the inability of the exocrine pancreas to produce and transport enough digestive enzymes for proper digestion and absorption. This can be the result of progressive pancreatic damage that may be caused by cystic fibrosis (CF), Shwachman-Diamond Syndrome, acute or chronic pancreatitis, and type 1 or autoimmune diabetes. Pancreatic insufficiency symptoms include malnutrition, malabsorption, steatorrhea, bulky stools, abdominal pain, flatulence, vitamin deficiencies, and failure to thrive. A useful indirect test for severe pancreatic insufficiency is Fecal Pancreatic elastase-1 (FE1), a proteolytic pancreatic enzyme, which binds to bile salts, and does not degenerate in the intestine. However, a secretin stimulation test is required for mild pancreatic insufficiency, since it has a higher sensitivity. We describe a two year old, full term male, with poor weight gain, eczema, and bloody diarrhea on presentation. Initially, he was diagnosed with cow's milk and soy protein allergy. Elemental formula was commenced which resolved the bloody diarrhea. However, he still continued to have rashes, poor growth, steatorrhea, and brittle hair. He also developed iron deficiency anemia and low vitamin D levels. He had abnormal qualitative fecal fat on two consecutive tests. FE1 was normal, and he underwent an endoscopy with secretin stimulation. Biopsies did not show any abnormal pathology; however, the pancreatic fluid showed isolated trypsin and chymotrypsin deficiency with an alkaline pH. Sweat chloride collection was normal. CF, Shwachman-Diamond, and Pearson syndrome were ruled out. His signs and symptoms improved on iron, vitamins, and pancreatic enzyme supplementation. In conclusion, isolated trypsin and chymotrypsin deficiency is an uncommon cause of poor growth and malabsorption, which can be successfully diagnosed with a secretin stimulation test. Successful treatment can be accomplished with pancreatic enzyme supplementation, iron, and vitamins.