The Ulaş family of nineteen from rural southern Turkey has been the primary example of the proposed syndrome.
In infants, where this is a rare stage prior and sometimes following bipedal walking, such a gait is called "bear crawl".
[1] In January 2008, Tan reported on another family (four males and two females) located in southern Turkey.
Uner Tan syndrome has been linked to intrafamilial marriage and reproduction, which suggests that it is an autosomal recessive disorder.
[3] The syndrome's main characteristic is habitual quadrupedalism, meaning they can stand up straight until they try to move, then they walk on their hands and knees.
[3] This simply means it is a type of disorder that involves the cerebellum becoming inflamed, resulting in lack of control of voluntary movements.
[3] Human geneticist Tayfun Ozcelik discovered homozygosity in a region on chromosome 9p24 in Uner Tan syndrome individuals.
[1] The very low density lipoprotein receptor gene (VLDLR) is located in this region, which is involved in the migration of neuroblasts within the brain.
This may affect the proper formation of cerebrocerebellar structures critical for upright walking, resulting in quadrupedal locomotion.
The researchers proposed a tentative reclassification of UTS into three types based on how they present themselves clinically.
In the VLDLR gene, similar mutations may be responsible for different types of cerebellar ataxias that affect proper locomotion in humans.