About 37 percent of people with pectus excavatum also have a close relative with the condition. This suggests that it may be hereditary. Pectus excavatum is the most common chest wall anomaly among children. In severe cases, it can interfere with the function of the heart and lungs.In mild cases, it can cause self-image problems. Some patients with this condition often avoid activities such as swimming that make hiding the condition difficult.his suggests that it may be hereditary. Pectus excavatum is the most common chest wall anomaly among children. In severe cases, it can interfere with the function of the heart and lungs. In mild cases, it can cause self-image problems.