Maternal inheritance pattern of hereditary pancreatitis in patients with pancreatic carcinoma.

Hereditary pancreatitis is an autosomal dominant disorder whose phenotype is associated with distinct point mutations in the cationic trypsinogen gene on chromosome 7q35 (1,2). Affected patients have recurrent episodes of pancreatitis that often begin during childhood. Compared with the general population or patients with chronic pancreatitis of common etiologies who have a somewhat increased cancer risk (3), patients with hereditary pancreatitis have a risk of developing pancreatic carcinoma that approaches 40% (4). Because all previously reported cases of pancreatic cancer associated with hereditary pancreatitis were diagnosed in patients who had inherited the disease from their father, the cumulative risk of developig cancer of the pancreas is considered to be even greater (approximately 75%) when hereditary pancreatitis is inherited from the father (4). In this correspondence, we report two kindreds with hereditary pancreatitis, each of which were affected by an R117H mutation of the trypsinogen gene, and in each case the patient with pancreatic cancer had inherited the defective cationic trypsinogen gene from the mother. When informed consent for genetic testing was obtained, R117H mutations were identified by the characteristic band pattern on ethidium bromidestained agarose gels after AflIII digestion of leukocyte DNA and confirmed by DNA sequencing as previously reported (1). In family 1 from the U.K. (Fig. 1, A), patient I:2 and her daughter