Familial congenital diaphragmatic hernia in the pig--studies on pathology and heredity.

Thirteen cases of congenital diaphragmatic hernia were encountered in one of the three pig families, established by us as a disease model of ano-rectal malformations. Five were males and 8 were females. The age at the onset of symptoms ranged between one and 4 months after birth. On the laterality, 7 had right side, 5 had left side and one had bilateral hernias. No hernial sac was observed. Herniated organs were intestine in the right and stomach in the left side. Thus congenital origin with late onset was suggested as a cause of the disease. In the studies of the heredity, there was no linkage between ano-rectal malformations and diaphragmatic hernia. Double recessive genes were supposed as a mode of inheritance, according to the statistical calculation. An effort is being made to produce a model of congenital diaphragmatic hernia from the pig family.