Inherited defect in hereditary pancreatitis.

Definite inherited defect in hereditary pancreatitis (HP) is not known. A new kindred with 3 definite and 6 suspected cases of HP was investigated for possible inherited abnormalities. No aminoaciduria (except for a slight rise in urinary histidine in one patient) and no hyperparathyroidism, hyperlipidemia, or chromosomal abnormality was present. An increase in serum IgM level of a polyclonal type was noted in 3 definitely affected sisters and also in 2 nonaffected members. Serum alpha-1-antitrypsin and serum trypsin inhibition were normal. However, very marked dilatation and ectasia of the pancreatic duct were found in the propositus. Reviewing the data from this family and previously described kindreds, it is postulated that the genetic abnormality in HP encompasses a wide variety of structural and anatomical defects in the sphincter of Oddi or the pancreatic ductal system. These predispose to intermittent obstruction of the duct with concomitant activation of enzymes and ductal metaplasia. In suspected cases an early effort should be made to outline the pancreatic duct as the defect may be amenable to surgery.