Pancreas, Annular

Clinical Features

Jackson and Apostolides (1978) described a family in which the mother and 3 of her 4 children had annular pancreas causing duodenal stenosis. In all 4, symptoms of high intestinal obstruction developed early in life and necessitated gastrojejunostomy or duodenojejunostomy. MacFadyen and Young (1987) described affected mother and son, both of whom presented in the neonatal period with gastrointestinal obstruction. The mother had undergone laparotomy at age 3 days. The son likewise was operated on at age 3 days. The descending duodenum was found to be stenotic in association with an annular pancreas. Montgomery et al. (1971) described an affected sib pair; however, since annular pancreas may be silent or present only in adult life, this does not necessarily represent recessive inheritance. It appears that no male-to-male transmission has been reported. Hendricks and Sybert (1991) described annular pancreas and duodenal obstruction in mother and daughter. Rogers et al. (1993) observed annular pancreas in a mother and daughter.

Claviez et al. (1995), like Montgomery et al. (1971), described annular pancreas in sibs. The pregnancy in each of 2 sisters was complicated by polyhydramnios that was drained. Intestinal obstruction was suspected from prenatal ultrasound studies. In both sisters laparotomy was performed at day 3 of life with confirmation of the diagnosis of annular pancreas. Duodenostomy was performed, followed by uneventful recovery.

Animal Model

Homozygous inactivation of the Indian hedgehog gene (IHH; 600726) in mice results in 42% annular pancreas (Hebrok et al., 2000), and inactivation of the Shh gene (SHH; 600725) in mice also leads to annular pancreas in certain genetic backgrounds (Ramalho-Santos et al., 2000). Gut malrotations and imperforate anus, often associated with annular pancreas in humans, are also found in Shh mutant mice.