Uner Tan syndrome
Encyclopedia
Uner Tan syndrome, Unertan syndrome or UTS is a syndrome
proposed by the Turkish
evolutionary biologist Uner Tan
. Persons affected by this syndrome walk with a quadrupedal locomotion and are afflicted with primitive speech and severe mental retardation
. Tan postulated that this is an example of "backward evolution
". The proposed syndrome was featured in the 2006 BBC2 documentary The Family That Walks On All Fours
.
of nineteen from rural southern Turkey
is the main example of the proposed syndrome. Tan described five members as walking with a quadrupedal gait using their feet and the palms of their hand
s. In infants, where this is a rare but a normal stage prior and sometimes following bipedal walking, such a gait is called "bear crawl". The affected family members are also severely mentally retarded and primitive in speech. Tan proposed that these are symptoms of Uner Tan syndrome.
However, Nicholas Humphrey
, John Skoyles
, and Roger Keynes
have argued that their gait is due to two rare phenomena coming together. First, instead of initially crawling as infants on their knees, they started off learning
to move around with a “bear crawl” on their feet. Second, due to their congenital brain impairment, they found balancing
on two leg
s difficult. Because of this, their motor development was channeled into turning their bear crawl into a substitute for bipedalism.
Habitually and genetically UTS differs from disequilibrium syndrome
(DES - Hagberg et al. (1972)), according to one publication.
, which is a normal phase in child gait development.
See for a review:
Uner Tan syndrome: history, clinical evaluations, ganetics, and the dynamics of human qaudrupedalism. The Open Neurology Journal, 2010, 4, 78-89.
Syndrome
In medicine and psychology, a syndrome is the association of several clinically recognizable features, signs , symptoms , phenomena or characteristics that often occur together, so that the presence of one or more features alerts the physician to the possible presence of the others...
proposed by the Turkish
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
evolutionary biologist Uner Tan
Uner Tan
Uner Tan is a Turkish neuroscientist and evolutionary biologist. He is best known for his discovery and study of the human quadrupedal condition he named the Uner Tan syndrome. He taught at Cukurova University until his retirement in 2004 and had previously taught at several other...
. Persons affected by this syndrome walk with a quadrupedal locomotion and are afflicted with primitive speech and severe mental retardation
Mental retardation
Mental retardation is a generalized disorder appearing before adulthood, characterized by significantly impaired cognitive functioning and deficits in two or more adaptive behaviors...
. Tan postulated that this is an example of "backward evolution
Atavism
Atavism is the tendency to revert to ancestral type. In biology, an atavism is an evolutionary throwback, such as traits reappearing which had disappeared generations before. Atavisms can occur in several ways...
". The proposed syndrome was featured in the 2006 BBC2 documentary The Family That Walks On All Fours
The Family That Walks On All Fours
The Family That Walks On All Fours is a BBC2 documentary that explored the science and the story of five individuals in the Ulas family in Turkey that walk with a previously unreported quadruped gait . The documentary was created by Passionate Productions and was broadcast on Friday 17 March 2006....
.
Ulas family
The Ulas familyUlas family
The Ulas family is a large Kurdish family of 19 from rural southern Turkey, five of whom walk on all fours with their feet and the palms of their hands in what is called a "bear crawl". Their quadrupedal gait has never been reported in anatomically intact adult humans. The gait is different from...
of nineteen from rural southern Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
is the main example of the proposed syndrome. Tan described five members as walking with a quadrupedal gait using their feet and the palms of their hand
Hand
A hand is a prehensile, multi-fingered extremity located at the end of an arm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs...
s. In infants, where this is a rare but a normal stage prior and sometimes following bipedal walking, such a gait is called "bear crawl". The affected family members are also severely mentally retarded and primitive in speech. Tan proposed that these are symptoms of Uner Tan syndrome.
However, Nicholas Humphrey
Nicholas Humphrey
Professor Nicholas Keynes Humphrey is an English psychologist, based in Cambridge, who is known for his work on the evolution of human intelligence and consciousness. His interests are wide ranging...
, John Skoyles
John Skoyles (scientist)
John Skoyles is a dyslexic neuroscientist and evolutionary psychologist. He initially studied philosophy of science at the London School of Economics and then did MRC funded research upon neuroscience and dyslexia at University College London....
, and Roger Keynes
Roger Keynes
Roger John Keynes FMedSci is a British medical scientist. He is a Fellow of Trinity College, Cambridge, and a professor within the Department of Physiology, Development and Neuroscience....
have argued that their gait is due to two rare phenomena coming together. First, instead of initially crawling as infants on their knees, they started off learning
Learning
Learning is acquiring new or modifying existing knowledge, behaviors, skills, values, or preferences and may involve synthesizing different types of information. The ability to learn is possessed by humans, animals and some machines. Progress over time tends to follow learning curves.Human learning...
to move around with a “bear crawl” on their feet. Second, due to their congenital brain impairment, they found balancing
Balancing
The concept of balancing derives from the Balance of Power Theory, the most influential theory from the realist school of thought, which assumes that a formation of hegemony in a multistate system is unattainable since hegemony is perceived as a threat by other states, causing them to engage in...
on two leg
Leg
Łęg may refer to the following places in Poland:*A former name for the town of Ełk *Part of the Czyżyny district of Kraków*Łęg, Pleszew County in Greater Poland Voivodeship...
s difficult. Because of this, their motor development was channeled into turning their bear crawl into a substitute for bipedalism.
Habitually and genetically UTS differs from disequilibrium syndrome
VLDLR-associated cerebellar hypoplasia
VLDLR-associated cerebellar hypoplasia is a rare autosomal recessive condition caused by a disruption of the VLDLR gene...
(DES - Hagberg et al. (1972)), according to one publication.
Four males, two females
In January 2008, Tan reported on another family (four males and two females) located in southern Turkey.Other
Four other unrelated cases in families are described in various degrees of UTS among tens of persons. Males are affected more than females. Some individuals are unaware of time, lack language, having severe mental retardation with no conscious experience and communicate by murky sounds. Two males are unable to stand up, while in other cases, can stand up but can not make a step when standing. Less severe cases use toe walkingToe walking
Toe walking refers to a condition where a person walks on his or her toes without putting much weight on the heel or any other part of the foot. Toe-walking in toddlers is common. These children usually adopt a normal walking pattern as they grow older...
, which is a normal phase in child gait development.
See also
- VLDLR-associated cerebellar hypoplasiaVLDLR-associated cerebellar hypoplasiaVLDLR-associated cerebellar hypoplasia is a rare autosomal recessive condition caused by a disruption of the VLDLR gene...
See for a review:
Uner Tan syndrome: history, clinical evaluations, ganetics, and the dynamics of human qaudrupedalism. The Open Neurology Journal, 2010, 4, 78-89.