It is the most common type of chest wall deformities or malformations. It is characterized by sinking of the chest wall inwards. It occurs in one in every 300-400 live births. It is 4 times more common in males than in females. Also, family history of 37% of the patients has this disease.
With the severe relocation of the chest wall through the back, sinking may occur on the anterior wall of the right ventricle of the heart. Furthermore, in severely sunken situations, the heart is usually relocated through the left.