Pectus excavatum (PE) or funnel breast is the most common congenital deformity of the chest wall, which occurs in about 1 in 400 births with a boy to girl ratio of 4: 1 to 3: 1. The etiology of PE is largely undefined, but there are numerous indications that genetic factors play a role in the development of PE. Up to 40% of patients report affected family members with similar congenital deformities. In many families, PE follows a pattern that would be compatible with an autosomal dominant or recessive pattern of inheritance. The data on the frequent occurrence of PE in family members fluctuate greatly and only a few genes associated with a PE have been identified so far.

Previous studies suggest that sulfation of proteoglycans plays a crucial role in the normal development of cartilage and bone and could therefore be crucial in the genesis of the disease. The main catalytic machinery responsible for the biosynthesis and breakage of sulfate esters in the proteoglycans consists of various enzymes and transporters. Mutations in Sphingosine Kinase 1 (SK1) and Sphingosine Kinase 2 (SK2) genes that encode the transmembrane transporters of sulfate or enzymes that are involved in 3'-phosphoadenosine 5'-phosphosulfate (PAPS) synthesis have been identified as the cause of several inherited diseases that all have skeletal system deformities.

Connections between chest wall deformities with syndromes (e.g. Marfan, Noonan), anomalies (e.g. Poland, Moebius) or associations (e.g. Cantrell Pentalogy, PHACE) are well known. In contrast, there have so far been hardly any genetic studies of the isolated congenital chest wall deformities. Epidemiological data are insufficient and only a few groups deal with the inheritance and the incidence of this disease when it occurs in isolation.

Inclusion Criteria:

• . All patients who are in the Altona Children's Hospital or in the University Hospital Hamburg. Funnel breast, keel breast, sternal cleft
• . A signed declaration of consent from the parents or legal guardians is available
• . The patient has given a declaration of consent

Exclusion Criteria:

• Confirmation of another diagnosis associated with chest wall deformities:

  1. Marfan syndrome
  2. Noonan syndrome
  3. Poland syndrome
  4. Moebius syndrome
  5. Cantrell Pentalogy
  6. PHACE association

All patients who presented themselves in the study hospitals with the diagnosis of a chest wall deformity (funnel breast, keel breast, sternum cleft)