Identification of protease-sensitive but not misfolding PNLIP variants in familial and hereditary pancreatitis.

Mutations in the PNLIP gene have recently been implicated in chronic pancreatitis. Several PNLIP missense variants have been reported to cause protein misfolding and endoplasmic reticulum stress although genetic evidence supporting their association with chronic pancreatitis is currently lacking. Protease-sensitive PNLIP missense variants have also been associated with early-onset chronic pancreatitis although the underlying pathological mechanism remains enigmatic. Herein, we provide new evidence to support the association of protease-sensitive PNLIP variants (but not misfolding PNLIP variants) with pancreatitis. Specifically, we identified protease-sensitive PNLIP variants in 5 of 373 probands (1.3%) with a positive family history of pancreatitis. The protease-sensitive variants, p.F300L and p.I265R, were found to segregate with the disease in three families, including one exhibiting a classical autosomal dominant inheritance pattern. Consistent with previous findings, protease-sensitive variant-positive patients were often characterized by early-onset disease and invariably experienced recurrent acute pancreatitis, although none has so far developed chronic pancreatitis.