Tracheoesophageal fistula (TEF) is a life-threatening condition in which there is an abnormal connection between the esophagus and trachea (windpipe). The esophagus and trachea run next to each other through the chest cavity. The esophagus carries food and saliva to the stomach, while the trachea carries air to the lungs. TEF can lead to severe and fatal lung complications. Saliva and gastric secretions can be aspirated into the lungs, and normal swallowing and digestion of food cannot occur. Most affected people are diagnosed immediately after birth or during infancy.

Symptoms may include frothy bubbles of mucus in the mouth and nose; episodes of coughing and choking; and worsening symptoms during feeding. TEF may be isolated, or it may occur with other physical or developmental abnormalities (most commonly, esophageal atresia). In many cases the cause is unknown but it has been associated with some chromosome disorders. In some cases it may be acquired later in life after a cancer, infection, ruptured diverticula, or trauma. Treatment includes immediate surgical repair with survival rates of almost 100%.

In most cases, tracheoesophageal fistula (TEF) is not inherited and there is only one affected person in a family. When TEF is isolated (i.e. does not occur with any other abnormalities), it is considered a multifactorial condition (caused by a combination of various genetic and environmental factors). However, in most isolated cases, no specific genetic changes or environmental factors have been proven to cause the condition.

When TEF occurs as a feature of a genetic syndrome or chromosome abnormality, it may follow the inheritance pattern and recurrence risk for the underlying condition. In these cases, it may be caused by changes in single genes or chromosomes, or it may be multifactorial.