An exceptional genealogy for hereditary chronic pancreatitis.

Nearly one hundred families affected with hereditary chronic pancreatitis (HCP) have been reported in the literature. However, the fact that the disease involved only a few members of each family limits the informativeness of these reports and accounts for the infrequency and disappointing results of pathogenetic and genetic research. Our study concerned an exceptional HCP genealogy which would seem to provide an ideal model for the detection of a genetic anomaly linked to the expression of the disease. We studied 249 members of a family (214 still alive), covering eight generations born between 1800 and 1993. According to the customary criteria, 63 had definite and 17 probable HCP. Fifty-eight members under 18 years of age were still susceptible to developing the disease. This series confirms the mode of autosomal dominant heredity with variable penetrance. The clinical features and disease course were typical, except that symptoms tended to appear earlier. The series represents the most extensive HCP genealogy compiled and is one of the largest families studied in the field of genetic disease, regardless of etiology. Blood samples were taken from 146 subjects to facilitate pathogenetic and genetic research.

The hereditary pancreatitis gene maps to long arm of chromosome 7.

Hereditary pancreatitis (HP) is an autosomal dominant disorder with incomplete penetrance characterized by recurring episodes of severe abdominal pain often presenting in childhood. Although this disorder has only been recently described, about 100 families have been documented worldwide. The pathophysiology of this disorder is unknown. Here, a large French family of 147 individuals (47 of whom were affected) from a four-generation kindred with HP has been examined and a genome segregation analysis of highly informative microsatellite markers has been performed. Linkage has been found between HP and six chromosome 7q markers. Maximal two point lod scores between HP and D7S 640, D7S 495, D7S 684, D7S 661, D7S 676 and D7S 688 were 4.00 (theta = 0.143), 5.85 (theta = 0.143), 4.91 (theta = 0.156), 8.58 (theta = 0.077), 8.28 (theta = 0.060), 4.40 (theta = 0.169), respectively. Multipoint linkage data combined with recombinant haplotype analysis indicated that the most likely order is: D7S 640-D7S 495-D7S 684-D7S 661-D7S 676-D7S 688, with the HP gene situated in the underlined region. As in all families reported in the literature, the clinical presentation of the disease is identical to the presentation of sporadic cases, one could expect that the knowledge of the HP gene could be a clue to pancreatitis in general. Based on its map position, this is the first step towards the positional cloning of the Hereditary Pancreatitis Gene (HPG).