The position of the internal organs of the "mirror baby" is completely opposite to that of ordinary people. What causes this?

In our common sense, the heart grows on the left side of the body, but some people's heart position is the opposite. In medicine, this is called "situs inversus".

Situs inversus can be divided into complete and partial situs inversus. If only the heart is in a different position than others, it is partial situs inversus. There is also a type of person whose heart, spleen, liver and other organs are mirror-symmetrical to those of normal people, and they are also called "mirror people". The probability of this happening is about one in a million.

On May 20, 2023, a couple in Wuhan gave birth to a "mirror baby". The baby's heart and spleen are located on the right side of the body, while the liver is on the left side. Except for the abnormal position of the internal organs, the baby is healthy.

Why do "mirror people" appear? The medical community has not yet reached a conclusion, but through clinical observation, doctors have also discovered certain patterns.

First of all, it is certain that the mirror man is formed during embryonic development. Once the embryo's internal organs are formed, they will not move.

Secondly, the cause of "mirror people" may be related to genes. Doctors have found that some mirror people suffer from Kartagner syndrome, which is a hereditary disease. People with this disease are prone to symptoms such as bronchiectasis, sinusitis, and situs inversus. This is because this disease causes the movement of cilia on cells to be impaired, and there are a large number of cilia in our respiratory tract. If there is no cilia movement to expel dust and germs in the air, it is easy to cause respiratory infections. Therefore, it has been reported in the news that some "mirror people" went to the hospital because of lung disease, only to find that the position of their internal organs was different from that of ordinary people.

However, not all "mirror people" are prone to health problems. Some "mirror people" have almost no obvious clinical symptoms. In fact, compared with patients with partial situs inversus, "mirror people" with complete situs inversus are healthier. This is because the position of the entire internal organs of mirror people is reversed, while the relationship between the internal organs has not changed. Therefore, many people find out that they are "mirror people" when they seek medical treatment for other diseases.

Normal position of human internal organs, picture from Tuchong.com

In the past, medical testing was not well developed, and many mirror people did not know that their body structures were different throughout their lives. There is such an example in the United States. After an old woman died at the age of 99, her body was sent to a medical school for dissection, and it was discovered that the position of her internal organs was different.

With the development of modern medicine, we can find out whether the fetus is a mirror person before birth. There are also many ways to determine whether the fetus has genetic diseases and whether the heart is developing normally, so please pay attention to prenatal examinations.

In addition, due to the different body structures of mirror babies, it is necessary to inform the doctor in time when seeking medical treatment. You should know that many of the hospital's equipment and even the doctor's surgical techniques are prepared for the normal position of internal organs. If you do not explain, it is easy for the doctor to misdiagnose or miss the diagnosis.

This article is a work supported by Science Popularization China Starry Sky Project

Author: Duan Yulong

Reviewer: Tao Ning (Associate Researcher, Institute of Biophysics, Chinese Academy of Sciences)

Produced by: China Association for Science and Technology Department of Science Popularization

Producer: China Science and Technology Press Co., Ltd., Beijing Zhongke Xinghe Culture Media Co., Ltd.