
Anterior Thoracic Dysplasia
As in Poland syndrome, there are problems with underdevelopment and absence of the breast on the affected side and underdevelopment or absence of structures in the chest wall. Unlike Poland syndrome, absence of pectoral muscle is not observed.

Spinal Muscular Atrophy (SMA)
Spinal Muscular Arophy (SMA) is also a genetic condition. It is a condition that affects the nervous system and therefore muscle movements and shows progressive features. It is rare. All SMA 1 patients and some SMA 2 patients may develop pectus excavatum if they are not treated in the early period due to the uncontrolled contraction of the diaphragm muscle, due to the fact that their rib cage collapses inward while breathing instead of expanding outward.

Charcot-Marie Tooth Disease
Charcot-Marie Tooth Disease is a disease associated with the nervous system. After the damage to the nerves outside the brain and spinal cord, weakness is observed in the hand and foot muscles. One of the components of this syndrome is pectus excavatum or other chest wall deformity and this component may accompany the disease.

Atelosteogenesis Syndromes
Atelosteogenesis Syndromes is a syndrome with various types. Their common feature is the presence of a problem related to the development of bones in the body. Affected individuals are born with feet that turn inward and upward (clubfoot) and dislocations of the hip, knee, and elbow. Bones in the spine, rib cage, pelvis, and limbs may be underdeveloped or in some cases absent. As a result of limb bone abnormalities, individuals with this condition have very short arms and legs. Various chest wall deformities and pectus excavatum may accompany as a result of affecting the sternum bone along with all bones.