People with their hands and feet on the ground; The four-legged syndrome, which causes them to walk on all fours, or Üner Tan syndrome, is a disease that was first observed in our country and entered the medical literature.
Thanks to the researches carried out by the evolutionary biologist Üner Tan on the disease, also known as the four-legged syndrome, this disease is called ‘Üner Tan Syndrome’ in medicine around the world. This precious evolutionary biologist passed away at the age of 85. We wanted to explain simply what the four-legged syndrome, named in his memory, is.
What is the four-legged syndrome / Üner Tan syndrome?
Uner Tan syndrome is a type of disease in which people experience loss of balance and coordination, along with cognitive disorders. Not everyone with Uner Tan syndrome walks on all fours, but they often lose their balance. You can see how people with Uner Tan syndrome walk in the video above.
What causes Uner Tan syndrome?
What causes Uner Tan syndrome is genetic. As you can imagine, consanguineous marriage also has a great impact on the occurrence of this disease. An autosomal recessive disorder occurs as a result of marriage and reproduction within the family. These disorders, which mean that a person receives two negatively altered (mutated) copies of the same gene from both parents, cause many diseases.
The usual basic feature of this syndrome, which is one of them, is quadrupedalism. People can stand on two legs, but when they want to move, they collapse on their hands and act as if they have the same four legs.
How was Uner Tan syndrome discovered?
The Ulaş family, the first family to have four-legged syndrome, was found in a small village near the Iskenderun district of Hatay. Later, families with this syndrome emerged in Adana, Gaziantep and two small villages near Çanakkale.
All individuals affected by Uner Tan syndrome had dynamic balance disorder during upright walking and it was revealed that they had a habit of walking on all fours. MRI scans showed inferior cerebellovermian hypoplasia with slightly simplified cerebral gyrus in three of the families, but appeared normal in the fourth family.
Uner Tan syndrome, ‘retrospective evolution’?
When Üner Tan discovered this condition, he called it ‘retrospective evolution’ and compared the gait of people with this syndrome to primates. However, the term backward evolution does not apply to Üner Tan syndrome.
This is because retrospective evolution means that a lineage ‘gradually’ regains the traits of its ancestors in its evolutionary process. So if we could evolve backwards, walking as a primate wouldn’t be in the first place.
The event that takes place in Uner Tan syndrome is considered as ‘atavism’ rather than evolution. If you are asking, “What is atavism?”, let’s answer that right away. Atavism is a type of change that can reveal the characteristics of any ancestor for 1 generation as a result of mutation. If this change is permanent, backward evolution begins. Atavism and backward evolution are related but not the same thing.
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