Genetic pancreatitis: PRSS1, SPINK1, CFTR and CTRC
- Mechanism
Some people inherit genes that let trypsin switch on too easily or stay active too long, so they get pancreatitis young and often.
What it is
Genetic variants explain many cases of recurrent acute and chronic pancreatitis in young people. Most act on the balance of trypsin activity in the pancreas: gain-of-function changes in cationic trypsinogen (PRSS1) make trypsin resistant to inactivation; loss of the trypsin inhibitor SPINK1 or of chymotrypsin C (CTRC) removes safety brakes; CFTR variants thicken pancreatic secretions. Hereditary pancreatitis from PRSS1 is autosomal dominant and carries a high lifetime risk of pancreatic cancer.
Step by step
- Small amounts of trypsinogen activate inside the pancreas every day.
- Normally SPINK1 binds the trypsin and CTRC and trypsin itself degrade it.
- PRSS1 mutations make trypsin resistant to this breakdown, or activate it more easily.
- SPINK1 or CTRC loss removes the safety brakes.
- Active trypsin persists and triggers repeated episodes of acute pancreatitis.
- Repeated injury leads to fibrosis, calcifications and chronic pancreatitis.
Genes of hereditary and genetic pancreatitis
| Gene | Normal role | Effect of the variant | Inheritance |
|---|---|---|---|
| PRSS1 | Cationic trypsinogen | Gain of function: trypsin activates easily or resists inactivation | Autosomal dominant |
| SPINK1 | Trypsin inhibitor | Loss of the inhibitor | Modifier, often recessive or complex |
| CTRC | Chymotrypsin C, degrades trypsin | Loss of degradation | Modifier |
| CFTR | Chloride and bicarbonate channel of duct cells | Thick secretions, duct plugging | Autosomal recessive |
Test yourself
Think of the answer, then tap the question to see it.
What kind of mutation in PRSS1 causes hereditary pancreatitis?
Gain-of-function mutations that make cationic trypsinogen activate easily or resist inactivation.
What does SPINK1 normally do?
It encodes the pancreatic secretory trypsin inhibitor, which binds and blocks trypsin activated inside the pancreas.
Which cancer risk is raised in hereditary pancreatitis?
Pancreatic ductal adenocarcinoma, especially in smokers.
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Connections
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Hereditary pancreatitis: MedlinePlus Genetics (MedlinePlus, US National Library of Medicine, 2026); Cystic fibrosis: MedlinePlus Genetics (MedlinePlus, US National Library of Medicine, 2026).
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Representative model, for educational purposes only.