Üner Tan Syndrome (UTS) is a disorder that was discovered by Üner Tan in 2005 from a family living in a village nearby Iskenderun of Southern Turkey. Üner Tan is a Turkish neuroscientist who taught at Çukurova University until he retired in 2004.
The syndrome that Dr. Tan discovered is characterized by quadrupedal gait, primitive speech, flexed head and body, mental retardation and disturbed conscious experience. The unique feature from the discovery is that the patients were from a family of consanguineous marriage. Discussion with patients and their family members by Dr. Tan and team that done the study revealed that after childhood they have not gained erect posture and bipedal gait.
Dr. Tan in another paper on Üner Tan Syndrome described this syndrome as an example of “reverse evolution” of humans. It seemed to be correct phrase for calling such a disease. But later on Shapiro et al. in 2014 falsified this “devolution” theory and explained that quadrupedal gait in UTS might have arisen as a result to overcome biomechanical constraints. Since 2005, many cases of UTS have been identified. Of these several cases have been identified by Dr. Tan itself. When first family was identified in Iskenderun, the second was in Adana, third in Gaziantep and fourth in Canakkale, all in Turkey.
Roger Keynes, Nicholas Humphrey and John Skoyles have criticized Dr. Tan’s use of “devolution” for describing the syndrome. Nicholas Humphrey stated it as:
“It’s terribly easy to be led away by some notion of living fossils…I’m not going to make any bones about this. I think that Professor Tan’s description of this family as a “devolution,” as an evolutionary throwback, is not only scientifically irresponsible, but is deeply insulting to this family.”
When genetic studies were conducted it revealed that VLDLR gene mutations cause cerebellar ataxia. VLDLR is known to help in neuroblast migration during development. Later several other genes were identified which have some other roles inside the body. One of them TUBB2B is responsible for microtubule stabilization in neurons and integral for cells’ movements to proper location in the brain. The mutation in this gene leads to destabilized microtubule and thus the neuronal cell. Other genes are CA8 and WDR4. The latter two genes have functions related to neuronal development. Mutations in this also cause ataxia and related symptoms. Sometimes the symptoms of UTS might overlap with that of Disequilibrium Syndrome (DES-H) and Cayman Syndrome.
The Biologist J 