[Congenital gastrointestinal diseases with manifestations in adulthood].

A genetic background is discussed in many disorders of the gastrointestinal tract with a disposition in addition to environmental factors. The pathophysiology of most hereditary diseases is unknown although the mode of inheritance is established. Biochemical analysis may show molecular defects or inborn lack of enzymes, cytogenetic studies may reveal chromosomal abnormalities. The knowledge of genetic factors in gastrointestinal disorders may contribute to the early detection of persons afflicted but not yet symptomatic, in some rare syndromes genetic counseling may become mandatory. Finally, there are many congenital malformations which may not cause symptoms for many years so that doubts may arise whether they are developmental anomalies or acquired conditions.