TAN, Prof. Dr. Uner and KARACA, Dr. Sibel and TAN, Assoc. Prof. Meliha and YILMAZ, Dr. Bekir and BAGCI, Dr. Namik Kemal and OZKUR, Dr. Ayhan and PENCE, Assoc. Prof. Sadrettin (2007) UNERTAN SYNDROME: A CASE SERIES DEMONSTRTAING HUMAN DEVOLUTION. [Preprint]

Full text available as:



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 intra-familial marriages suggested that the UTS is an autosomal recessive disorder. 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, answering them 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 (DES). 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. 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. Since 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.

Item Type:Preprint
Keywords:Unertan syndrome, quadripedality, scissoring gait, toe-gait, language impairment, ataxia, cerebellar hypoplasia, vermial hypoplasia
Subjects:Biology > Evolution
JOURNALS > Behavioral & Brain Sciences
ID Code:5444
Deposited By:Tan, Prof. Dr. Uner
Deposited On:07 Mar 2007
Last Modified:11 Mar 2011 08:56

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.

Boyles, A., L., Billups, A. V., Deak, K. L., Siegel, D. G., Mehltretter, L., et al. (2006). neural tube defects and folate pathway genes: family-based association tests of

gene-gene and gene-environment interactions.

Chen, C. P., Chern, S. R., Lee, C. C., Chen, W. L., & Wang, W. (2001). Prenatal diagnosis of mosaic ring chromosome 13 with anencephaly. Prenatal Diagnosis, 21, 102-195.

Detrait, E.R., George, T. M., Etchevers, H. C., Gilbert, J. R., Vekemans, M., & Speer, M. C. (2005). Human neural tube defects: developmental biology, epidemiology, and

Genetics. Neurotoxicology and Teratology, 27, 515-524.

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.

Hagberg, B., Sanner, G., & Steen, M. (1972). The dysequilibrium syndrome in cerebral palsy, Clinical aspects and treatment. Acta Pediatrica Scandinavia, 61 suppl. 226), 1-63.

Hahm, G. K., Barth, R., Schauer, G. M., Reiss, R., & Opitz, J. M. (1999). Trisomy 2p 18 syndrome: a fetus with anencephaly and postaxial polydactyly. American Journal of

Medical Genetics, 87, 45-48.

Hof, At. L., 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.

Koukoura, O., Sifakis, S., Stratoudakis, G., Mantas, N., Kaminopetros, P., & Koumantis, E. (2006). Clinical and experimental obstetrics & gynecology, 33, 185-189.

Lemire, R. J. (1988). Neural tube defects. JAMA, 259, 558-562.

Lomholt, J. F., Fisher-Hanen, B., Keeling, J. W., Reintoft, I., & Kjaer, I. (2004). subclassification of anencephalic human fetuses according to morphology of the posterior cranial fossa. Pediatric and Developmental Pathology, 7, 601-606.

Lynch, S. A. (2005). Non-multifactorial neural tube defects. A erican Journal of Medical Genetics, Part C, 135C, 69-76.

Mezhzherin, S. V. (1997). Gradualism or puntualism: data on genetic differentiation of small mammals from the Holarctic region. Genetika, 33, 518–523.

Minghetti, P. P., & Dugaiczyk, A. (1993). The emergence of new DNA repeats and the divergence of primates. Proceedings of National Academy of Sciences, U.S.A., 90,


Mitchell, L. E. (2005). Epidemiology of neural tube defects. American Journal of Medical Genetics, 135C, 88-94.

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

Polanski, J. M., & Franciscus, R. G. (2006). Patterns of craniofacial integration in extant homo, pan, and gorilla. American Journal of Physical Anthropology, 131, 38-49.

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.

Rushton, J. P., & Ankney, C. D. (2000). Size matters: a review and new analysis of racial differences in cranial capacity and intelligence that refute Kamin and Omari. Personality and Individual Differences, 29, 591-620.

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. (1985). 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. (2005a). Ünertan Senromu ve insane ruhunun evri,mine ilişkin yeni bir teori. Biyobank, 3. sayı, 15 November, 2005.

Tan, U. (2005b). Unertan Syndrome; qaudrupedality, 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 “Üner Tan Syndrome”: a theory for possible mechanisms of human devolution toward the atavistic walking patterns. International Journal of Neuroscience, 117, 147-156.

Tan, U., Pence, S., Yılmaz, M., Ozkur, A., Karaca, S., Tan, M., & Karatas, M. (2007). “Üner 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.

Tasdelen, E., Arvas, A., Perk, Y., & Ilter, O. (1996). An evaluation of the cases of neural tube defects. Cerrahpasa Journal of Medicine, 27, 59-62.

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.

Wahlsten, D. (1999). Single-gene influence on brain and behavior. Annual Review of Psychology, 50, 599–624.


Repository Staff Only: item control page