The vast majority of people, speaking of the heart, put their hand on the left side of the chest. However, in 1643, the Italian surgeon Marco Severino described the first case of the location of the heart on the right in the history of mankind, and after another 50 years the first case of a complete transposition of internal organs, better known as mirror disease, was described. With this disease, the location of the internal organs is a mirror image of the normal. So, the heart is located on the right, its apex is also turned to the right, the stomach is on the right, but the gall bladder and liver, on the contrary, are on the left. The intestines, blood and lymph vessels, nerves are also located in mirror image. It affects mirror syndrome and seemingly symmetrical lungs: the right has 2 lobes, and the left has 3.
Naturally, becoming interested in this anatomical anomaly, people began to look for its causes. In the Middle Ages, mirror disease was attributed equally to the machinations of the devil and the gifts of God. And only much later, scientists found an explanation for this mysterious phenomenon and associated it with primary ciliary dyskinesia and Cartagener syndrome. In general terms, mirror syndrome is a genetically determined disease associated with impaired activity of the ciliary epithelium due to a congenital defect in their morphology. With this pathology, a mutation occurs in 12 different genes that encode the synthesis of proteins necessary for the construction and correct function of the cilia. As a result of this, patients have respiratory disorders, since it is difficult to discharge mucus from the respiratory tract, and infertility is also common in men (less often in women).
In the process of embryonic development of the fetus, it is precisely the movement of the cilia that determines the axis relative to which the laying of organs occurs, and therefore, in the event of a violation of the function of the cilia, transpositions occur. Like most other genetic pathologies, mirror disease is characterized by an autosomal recessive type of inheritance, and therefore its frequency is extremely low: from just 1 case per 10,000 people to 1 case per 60,000.
Sometimes, in especially difficult situations, an incomplete transposition of internal organs is observed: they are all mirrored, and the heart is still on the left. In 95% of cases of this morphology, patients suffer from various congenital heart defects. As for other cases of mirror syndrome, it has virtually no scientifically proven effect on health, quality and life expectancy. Only some discomfort is possible because a person, as a rule, does not suspect such a peculiarity, and therefore, if there are health problems, doctors have seemingly significant difficulties in diagnosing diseases.
However, the current level of development of medicine has allowed doctors not only to diagnose organ transposition in humans, but also to do genetic analysis to identify mutations in target genes. The main problem that people with a diagnosis of "mirror disease" may face is organ transplantation. Due to the rarity of the disease, finding a potential donor is quite difficult, and often not at all possible.
It is worth noting the fact that organ transposition is found not only in humans, but also among representatives of the animal world, for example, snails. So, a grape snail, as a rule, has a shell twisted to the right, however, individuals with a shell twisted to the left are found with a frequency of 1 in 10,000 - 1 in 100,000.
In addition, mirror disease is an excellent basis for superstition. Despite the fact that the Middle Ages have long sunk into oblivion, many people still believe that patients with transposition of organs have supernatural abilities, and official science, in turn, continues to enthusiastically study the factors that cause such a specific mutation of the genome.