Top 7 Causes of Pectus Excavatum – Is it Genetic? & More

Evidence Based This post has medical citations

What causes pectus excavatum?

The specific cause of pectus excavatum is still unknown. It probably originates from a genetic defect that results in abnormal musculoskeletal growth.

The cartilaginous part of the rib cage is possibly the main source of this strange growth pattern. Malformations of rib morphogenesis and development are the most likely causes of pectus excavatum and pectus carinatum.

It is mostly described as genetic, with one’s family history being the main indicator of risk for the deformity. However, there are other medical conditions closely related to pectus excavatum.

Health professionals and scientists are working hard to find out the precise reason why this chest wall deformity occurs. Studies need to reveal the root of the deformity so that a cure can be found for future prevention.

However, the studies did reveal that other medical conditions are closely related to pectus excavatum. Also, doctors and scientists figured out ways to repair the deformity.

If you suffer from it, feel thankful that you live in this day and age, because only a few decades ago, there wasn’t a real solution for this deformity.

7 Most Common Causes of Pectus Excavatum

1. Genetics

pectus excavatum is inherited

A small size study done at the Harvard Medical School, by Robert C. Shamberger in 1996, showed that 37% to 47% of all pectus excavatum patients have an affected first-degree relative also suffering from the deformity. (1)

Research done on families revealed an inheritance by autosomal dominant, autosomal recessive, X-linked, and multifactorial inheritance in different relatives. So, if your mother and father have a hollow chest, there is a 37% to 47% probability that you’ll also have it.

This study categorizes the pectus excavatum deformity and rib flare posture, as mostly genetic. Another study done in 2012 found plenty of other genetic markers for inverted chest deformities. This study found that roughly 43% of patients with pectus excavatum have a family member with a comparable defect. (2)

In 1934, a student at Ohio State University showed his strange-looking chest. Scientists were interested in it and decided to do an examination. It was revealed that eight other members of his family had very similar conditions.

They chose to name this deformity “koilosternia.” (3) This is the same malformation as pectus excavatum. Scientists Snyder and Curtis concluded that this deformity followed an autosomal dominant pattern of inheritance.

In 1939, Edmund Stoddard noticed genetic transmission of the deformity in a single family, with 49 cases of pectus excavatum extending over four generations. This researcher also assumed autosomal dominant spreading. (4)

Recently, in 2006, a researcher by the name of HA Creswick issued the first significant family research of pectus excavatum. In this study, 34 families were investigated. (5) Fourteen families displayed the autosomal dominant heritage of pectus excavatum. Four showed autosomal recessive inheritance, and six were X-linked.

Creswick discovered that some cases were inherited through Mendelian genetics. However, most appeared multifactorial. The results of these studies unanimously suggest a genetic cause for pectus excavatum.


Numerous scientific studies revealed a direct connection between pectus excavatum and genetics.

2. Marfan Syndrome

pectus excavatum with marfan syndrome

Research has also revealed that 70% of patients with Marfan syndrome suffer from pectus excavatum. Researchers have reported that these patients experience an increased susceptibility to disease and mental anxiety. The sad thing is that it can get worse with age. (6)

Marfan syndrome is a hereditary disorder that acts on the connective tissue. This tissue connects, separates and supports all other types of tissues in the body. Additionally, it plays a massive part in the proper development and growth of the body.

Around 1 in 5000 people suffer from Marfan syndrome. It is an inherited mutation that impacts both males and females from all racial and ethnic groups. Statistics show that around 3 out of 4 people with Marfan syndrome have inherited it. Usually, it is transferred to the children from a parent who suffers from it.

The main characteristics of Marfan Syndrome are complications in the joints, bones, and ligaments. If you have pectus excavatum and suffer from pain in these areas, it is critically important to consult your doctor. Along with that, the bones may be longer than usual. Generally, the ligaments are becoming stretchy – like a rubber band.

These patients can also have some other skeletal abnormalities that should be examined by an orthopedic specialist. Because the bones can grow extra-long, pectus excavatum and carinatum are more likely to occur. It is very important for patients with Marfan syndrome to receive early and precise diagnosis. Without a prompt diagnosis, the resulting health complications can be deadly.

Receiving early treatment is critically important if you have Marfan syndrome. The pectus excavatum deformity in patients with Marfan syndrome can be fixed by surgical and non-surgical treatment. (7)

However, the nature of connective tissue sickness makes the chest wall bone structure flexible. There is a higher chance of sunken chest re-occurrence after a surgical procedure.

Because of this, the Nuss bar should stay underneath the sternum for a prolonged time. Studies suggest that surgical correction should be postponed until skeletal maturity is reached.


Roughly 70% of all Marfan Syndrome patients suffer from pectus excavatum. They can choose to fix it surgically or non-surgically.

3. Spinal Muscular Atrophy

Spinal muscular atrophy (SMA) is a combination of neuromuscular diseases that lead to the loss of motor neurons and gradual weakening of the muscles. SMA is divided into five categories, depending on the severity.

All Spinal Muscular Atrophy (SMA) type 1 patients and all those with SMA type 2 with paradoxical respiration can develop pectus excavatum if left untreated. (8) This is caused by the action of the diaphragm that is not regulated by the intercostal muscles.

As the diaphragm contracts, the stomach expands. The “Bucket handle” action of its insertion on the lower ribs creates an external expansion. This causes the upper chest to sink in.

The result is a sunken chest with the xiphoid process retracted and difficulty in the lungs’ development. The patients with Spinal Muscular Atrophy type 2 retain the capacity to sit unsupported for a limited period.

However, they can develop a breathing failure during their childhood. If left untreated, this can lessen life expectancy and cause problems in later life. Patients with SMA type 3 can walk, and they hardly ever have difficulties in breathing, or pectus excavatum.

To fix pectus excavatum, and stimulate natural lung growth, as well as normal chest wall development, a high-span positive inspiratory pressure along with positive end-expiratory pressure (PIP+PEEP) is used.

After a successful establishment of high-span PIP+PEEP, pectus excavatum improves in SMA patients. Also, the lungs and chest wall start to grow ordinarily.


Patients suffering from SMA Type I and II have the highest chance of having pectus excavatum. If left untreated, PE can cause breathing failure which can be life-threatening.

4. Noonan Syndrome

Sternal abnormalities in patients with Noonan syndrome are present in about 75% to 90% of all sufferers. They either have pectus excavatum or pectus carinatum. Also, the majority of these patients have scoliosis.

Noonan syndrome is a genetic disorder that influences many areas of the body. It manifests itself with skeletal abnormalities, atypical facial features, small stature, heart problems, and bleeding issues.


Noonan syndrome is a direct cause of pectus deformities.

5. Loeys-Dietz syndrome

Similarly to the Marfan syndrome, Loeys-Dietz syndrome affects the connective tissue in many parts of the body. The connective tissue gives strength and flexibility in the bones, ligaments, blood vessels, and muscles.

Sternal abnormalities are very typical in connective tissue disorders. This is the second most common connective tissue syndrome that causes pectus excavatum. Depending on the severity, the Loeys-Dietz syndrome is categorized into five types, starting from Type I to V.

Patients with Loeyz-Dietz syndrome have detectable musculoskeletal problems. They either have an inverted chest (pectus excavatum) or a chest that sticks out (pectus carinatum). They also have craniosynostosis, scoliosis, kyphosis, a foot that turns inward and upward, flat feet, and lengthened arms and legs with joint malformations.


Most Loeys-Dietz syndrome patients have muscuoskeletal problems. A high percentage of them have either pectus carinatum or excavatum.

6. Ehlers–Danlos Syndrome

Ehlers-Danlos syndrome is a set of illnesses that upset the connective tissue of the sufferer. It is inherited and frequently linked to pectus excavatum. It also affects the skin, bones, blood vessels, and other vital organs and tissues.

All flaws in the connective tissue cause severe symptoms of similar conditions. The signs of EDS can range from slightly wobbly joints to life-endangering difficulties.

An extraordinarily high range of joint motion (hypermobility) is present in all patients suffering from this syndrome. Kids and babies with hypermobility typically have weak musculature.

This stops them from developing fundamental motor skills such as walking, sitting, and standing. Their joints are usually very loose, unstable, and prone to dislocation and lasting agony. Babies suffering from this syndrome typically have dislocated hips at birth.

Scientific research unveiled that the minimally invasive Nuss procedure gives high functional and beautifying results in patients with Ehlers-Danlos syndrome. (9) There are strong indications that pectus excavatum correctional surgery was both harmless and efficient in EDS patients.

The success rate of the caved-in chest operation in patients with connective tissue disorders is the same as people without these illnesses. However, the Nuss bar dislocation chance is insignificantly higher in patients with connective tissue disorders.

Even though the Nuss procedure with costal cartilage chondrotomy resulted in notable cosmetic improvements for patients with unequal PE, surgeons should be alert of the possibility of continual pleural effusion after the procedure in patients with EDS.


Ehlers-Danlos syndrome is a connetive tissue disorder. These patients mostly suffer joint hypermobility. Science has proven that there is a direct correlation between EDS and pectoralis excavatum.

7. Celiac disease

Pectus excavatum occurs in about 1% of people diagnosed with a Celiac illness. As of 2020, the causes remain unknown. Celiac disease is an immune system illness. It makes patients unable to eat gluten because it will hurt their small intestine.

If you’re suffering from this disease and you consume foods that contain gluten, then your immune system will respond, harming your small intestine. This disease is inherited. It affects every sufferer slightly differently.

Most of the signs appear in the digestive system or other areas in the body. Also, it can be psychologically disturbing. Some patients suffer from depression, while others only feel abdomen pain and diarrhea.

Some people won’t feel any symptoms at all. The best treatment of Celiac disease is to consume gluten-free food.


1% of all Celiac Disease sufferers have pectus excavatum. It’s an illness that leaves a negative psychological effect on the patient.

Honorable Mention – Scoliosis / Poor posture

Scoliosis and poor posture are closely connected with pectus excavatum. However, no scientific evidence proved that pectus excavatum occurs because of scoliosis and bad posture.

But, if a patient suffers from pectus excavatum and his posture or scoliosis gets worse, then the severity of the deformity will improve. It is critically important to improve your posture and strengthen the postural muscles in the back.

Look at the posture of pectus excavatum sufferers. What you’ll see is what people call “pectus posture” appearance. Thanks to our Nine-To-Five jobs, school, and improper sitting habits, we tend to forget how important posture is to humans.

Bad posture and scoliosis will lead to physical suffering like back and sternal pain and psychological problems like depression and anxiety. If you have the pectus excavatum deformity, make sure you check how you carry your body in your everyday life.

Are your shoulders slouching?

Do you have an anterior pelvic tilt?

Do you have a forward head posture?

All these are indicators of a poor posture. If you do, check out this specific concave chest workout plan. They will help you improve your poor posture, boost your happiness, positive self-image and, most importantly, help you fix your pectus excavatum condition.

Concave chest anxiety will be gone as a result.

How I Fixed My Hereditary Pectus Excavatum

Don’t be discouraged by people who claim that pectus excavatum is not treatable without surgery. The way you can fix it isn’t only by undergoing painful and expensive surgery that costs around $40,000.

There is plenty of scientific evidence that proves this. The non-surgical correction consists of physical therapy, wearing corrective orthoses, vacuum bell therapy, and stretching the tight muscles that worsen your posture through yoga.

This was the approach that I decided to take. You can check my story to see how I managed to correct my mild pectus excavatum without an operation. I was terrified of taking surgery. I couldn’t handle the thought that I’d have a pectus bar underneath my breastbone for three long years.

Also, I couldn’t play any contact sports during the time because of the chance of bar dislocation. If the bar is dislocated, it may rupture critical vital organs and blood vessels, which can lead to death.

Thanks to my fear of surgery, I managed to fix my deformity in less than a year with proper research, dedication, consistency, and iron will! You can do it too!


You don’t have any control whether you’ll be born with pectus excavatum or not. As you can see, the pectus excavatum cause is mostly genetic. Other reasons are the consequences of rare diseases. Usually, people with these rare diseases have more significant concerns to deal with than pectus excavatum.

You should even feel grateful that your indented chest deformity is genetic. If your deformity is inherited, please accept your body as it is.

Every single person on this planet is insecure about something. Even some of the biggest adult Hollywood movie stars have a lack of confidence.

Learn to love yourself. As cliché as it sounds, it could’ve been worse.


1. Shamberger, R. C. (1996) ‘Congenital chest wall deformities’, Current Problems in Surgery, 33(6), pp. 469–542. doi: 10.1016/S0011-3840(96)80005-0.

2. Brochhausen, C. et al. (2012) ‘Pectus excavatum: history, hypotheses and treatment options’, Interactive CardioVascular and Thoracic Surgery, 14(6), pp. 801–806. doi: 10.1093/icvts/ivs045.

3. Dean, C. et al. (2012) ‘Pectus excavatum (funnel chest): a historical and current prospective’, Surgical and Radiologic Anatomy, 34(7), pp. 573–579. doi: 10.1007/s00276-012-0938-7.

4. Stoddard, S. E. (1939) ‘The Inheritance of “Hollow Chest”’, Journal of Heredity, 30(4), pp. 139–141. doi: 10.1093/oxfordjournals.jhered.a104698.

5. Creswick, H. A. et al. (2006) ‘Family study of the inheritance of pectus excavatum’, Journal of Pediatric Surgery, 41(10), pp. 1699–1703. doi: 10.1016/j.jpedsurg.2006.05.071.

6. De Maio, F. et al. (2016) ‘Orthopaedic Aspects of Marfan Syndrome: The Experience of a Referral Center for Diagnosis of Rare Diseases’, Advances in Orthopedics, 2016, pp. 1–6. doi: 10.1155/2016/8275391.

7. Fraser, S., Child, A. and Hunt, I. (2018) ‘Pectus updates and special considerations in Marfan syndrome’, Pediatric Reports, 9(4). doi: 10.4081/pr.2017.7227.

8. Bach, J. R. and Bianchi, C. (2003) ‘Prevention of Pectus Excavatum for Children with Spinal Muscular Atrophy Type 1’, American Journal of Physical Medicine & Rehabilitation, 82(10), pp. 815–819. doi: 10.1097/01.PHM.0000083669.22483.04.

9. Masahata, K. et al. (2017) ‘Nuss procedure for a case of asymmetric pectus excavatum associated with Ehlers-Danlos syndrome’, Journal of Pediatric Surgery Case Reports, 22, pp. 20–24. doi: 10.1016/j.epsc.2017.05.004.

Article by:

Mihail Veleski

My name is Mihail Veleski. I used to suffer from the pectus excavatum deformity during my teenage years.

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