Definition of Treacher-Collins syndrome:

Treacher-Collins syndrome is a hereditary condition that causes facial defects.

Causes, incidence, and risk factors:

Treacher-Collins syndrome is caused by a defective protein called treacle. The condition is inherited as an autosomal dominant trait. More than half of all cases are thought to be due to new mutations because there is no family history of the disease.

This condition may greatly vary in severity from generation to generation.