Tan, Prof. Dr. Uner and Karaca, Dr. Sibel and Tan, Dr. Meliha (2007) UNERTAN SYNDROME: A CASE SERIES DEMONSTRATING HUMAN DEVOLUTION. [Journal (Paginated)]

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A large family with six individuals exhibiting the Unertan syndrome (UTS)was identified residing in southern Turkey. All of the individuals had mental impairments and walked on all four extremities. The practice of intra-familial marriages suggested that theUTS may be an autosomal recessive disorder, similar to previously described cases. The inferior portions of the cerebellum and vermis were absent as evidenced by MRI and CT scans. The height and head circumference of those affected were within normal ranges. Barany’s test suggested normal vestibular system function. The subjects could not name objects or their close relatives. The males (n = 4) could understand simple questions and commands, but answered questions with only one or two sounds. The females (n = 2) were superior to the males with respect to language skills and walking, suggesting an association between walking and speaking abilities. One male exhibited three walking patterns at the same time: quadripedal, tiptoe, and scissor walking. Another male used two walking styles: quadripedal and toe-walking. It is emphasized that there are important differences between the UTS and the disequilibrium syndrome. It is suggested that the inability to walk upright in those affected with the UTS may be best explained by a disturbance in lateral-balance mechanisms,without being related to the cerebello-vestibular system.An interruption of locomotor development during the transition from quadripedality to bipedality may result in habitual walking on all four extremities and is normal in some children. Because quadripedal gait is an ancestral trait, individuals with the UTS, exhibiting a manifestation of reverse evolution in humans, may be considered an experiment of nature, useful in understanding the mechanisms underlying the transition from quadripedality to bipedality during human evolution. The proposed mutant gene or gene pool playing a role in human quadrupedality may also be responsible for human bipedality at the same time. Herein there is no intent to insult or injure; rather, this report is an endeavor to better understand human beings. Supplementary materials are available for this article. Go to the publisher’s online edition of International Journal of Neuroscience for the following free supplemental resource(s): video clips.

Item Type:Journal (Paginated)
Keywords:ataxia, cerebellar hypoplasia, language, quadrupedality, scissoring gait, toe-gait, Unertan syndrome, vermial hypoplasia
Subjects:Neuroscience > Neurology
Neuroscience > Neuropsychiatry
ID Code:5858
Deposited By: Tan, Prof. Dr. Uner
Deposited On:10 Dec 2007 21:45
Last Modified:11 Mar 2011 08:57

References in Article

Select the SEEK icon to attempt to find the referenced article. If it does not appear to be in cogprints you will be forwarded to the paracite service. Poorly formated references will probably not work.

Bense, S., Deutschlaender, A., Stephan, Th., Bartenstein, P., Schwaiger, M., Brandt, Th., & Dieterich, M. (2004). Preserved visual-vestibular interaction in patients

with Bilateral Vestibular failure. Neurology, 63, 122–128.

Boycott, K. M., Flavelle, S., Bureau, A., Glass, H. C., Fujiwara, T. I.,Wirrell, E., Davey, K., Chudley, A. E., Scott, J. N., McLeod, D. R., & Parboosingh, J. S. (2007).

Homozygous deletion of the very low density lipoprotein receptor gene causes autosomal recessive cerebellar hypoplasia with cerebellar gyral simplification.

The American Journal of Human Genetics, 77, 477–483.

Caselli, M. A., Rzonca, E. C., & Lue, B. Y. (1988). Habitual toe-walking: Evaluation and approach to treatment. Clinics in Pediatric Medicine and Surgery, 5, 547–549.

Dieterich, M., Bense, S., Lutz, S., Drzezga, A., Stephan, T., Bartenstein, P., & Brandt, T. (2003). Dominance for vestibular cortical function in the non-dominant

hemisphere. Cerebral Cortex, 13, 994–1007.

Elena, S. F., Cooper, V. S., & Lenski, R. E. (1996). Punctuated evolution caused by selection of rare beneficial mutations. Science, 272, 1802–1804.

Glass, H. C., Boycott, K. M., Adams, C., Barlow, K., Scott, J. N., Chudley, A. E., Mary, T., Morgan, K., Wirrell, E., & McLeod, D. R. (2005). Autosomal recessive cerebellar Hypoplasia in the Hutterite population. Developmental Medicine & Child Neurology, 47, 691–695.

Guillou, E., Dupui, P., & Golomer, E. (2007). Dynamic balance sensory motor control and symmetrical or asymmetrical equilibrium training. Clinical Neurophysiology,

118, 317–324.

Hagberg, B., Sanner, G., & Steen, M. (1972). The dysequilibrium syndrome in cerebral palsy, Clinical aspects and treatment. Acta Pediatrica Scandinavia, 61(suppl. 226),


Hall, J. E., Salter, R. B., & Bhalla, S. K. (1967). Congenital short tendo calcaneous. Journal of Bone and Joint Surgery, 49B, 695–697.

Hof, At., van Bockel, R. M., Schoppen, T., & Postema, K. (2007). Control of lateral balance in walking, experimental findings in normal subjects and above-knee amputees. Gait & Posture, 25, 250–258.

Hrdlicka, A. (1928). Children running on all fours. American Journal of Physical Anthropology, 11, 149–185.

Pallister, P., & Opitz, J. (1986). Brief clinical report: Disequilibrium syndrome in Montana Hutterites. American Journal of Medical Genetics, 22, 567–569.

Porter, M. L., & Crandall, K. A. (2003). Lost along the way: The significance of evolution in reverse. Trends in Ecology and Evolution, 18, 541–547.

Riley, P. O., & Kerrigan, D. C. (2001). The effect of voluntary toe-walking on body propulsion. Clinical Biomechanics, 16, 681–687.

Sanner, G. (1973). The disequilibrium syndrome: A genetic study. Neuropediatrie, 4, 403–413.

Schurig, V., Oram, A. V., & Bowen, P. (1981). Nonprogressive cerebellar disorder with mental retardation and autosomal recessive inheritance in Hutterites. American

Journal of Medical Genetics, 9, 43–53.

Tan, U . (1985a). Relationship between hand skill and the excitability of motoneurones innervating the postural soleus muscle in human subjects. International Journal

of Neuroscience, 26, 289–300.

Tan, U . (1985b). Left-right differences in the Hoffmann reflex recovery curve associated with handedness in normal subjects. International Journal of Psychophysiology,

3, 75–78.

Tan, U . (1990). There is a close relationships between hand skill and the excitability of motor neurons innervating the postural soleus muscle in left-handed subjects. International Journal of Neuroscience, 51, 25–34.

Tan, U . (2005a). Unertan Senromu ve insan ruhunun evrimine iliskin yeni bir teori. Biyobank, 3. sayı, 15 November 2005.

Tan, U . (2005b). Unertan Syndrome; quadrupedality, primitive language, and severe mental retardation; a new theory on the evolution of human mind. NeuroQuantology

, 4, 250–255.

Tan, U . (2006a). A new syndrome with quadrupedal gait, primitive speech, and severe mental retardation as a live model for human evolution. International Journal of

Neuroscience, 116, 361–369.

Tan, U . (2006b). Evidence for “Unertan Syndrome” and the evolution of the human mind. International Journal of Neuroscience, 116, 763–774.

Tan, U . (2006c). Evidence for “Uner Tan Syndrome” as a human model for reverse

evolution. International Journal of Neuroscience, 116, 1433–1441.

Tan, U . (2007). A wrist-walker exhibiting no “U¨ ner Tan Syndrome”: A theory for possible mechanisms of human devolution toward the atavistic walking patterns.

International Journal of Neuroscience, 117, 147–156.

Tan, U ., Penc¸e, S., Yılmaz, M., O¨ zkur, A., Karaca, S., Tan, M., & Karatas¸, M. (2007). Uner Tan Syndrome” in two Turkish families in relation to devolution and

emergence of homo erectus: Neurological examination, MRI and PET scans. International Journal of Neuroscience,in press.

Teotonio, H., & Rose, M. R. (2000). Variation in the reversibility of evolution. Nature, 276(408), 463–466.

Teotonio, H.,& Rose, M. R. (2001). Perspective: Reverse evolution. Evolution, 55(278), 653–660.

Teotonio, H., & Rose, M. R. (2002). Reverse evolution of fitness in Drosophila melanogaster. Journal of Evolutionary Biology, 15, 608–617.

Tidwell, M. (1999). The child with tip-toe gait. International Pediatrics, 14, 235–238.

Turkmen, S., Demirhan, O., Hoffmann, K., Diers, A., Zimmer, C., Sperling, K., & Mundlos, S. (2006). Cerebellar hypoplasia and quadrupedal locomotion in humans

as a recessive trait mapping to chromosome 17p. Journal of Medical Genetics, 43, 461–464.

Tvrdik, P., & Capecchi, M. R. (2006). Reversal of Hox1 gene subfunctionalization in the mouse. Developmental Cell, 11, 239–250.


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