BBC Horizon Family That Walks On All Fours (2006).MP4

The Family That Walks On All Fours is a 2006 BBC documentary which examines five individuals in the Ulas family, in Turkey, who walk with a previously unreported quadruped gait.

There is debate about the nature and cause of their walking, including speculation that the Uner Tan syndrome may be a genetic throwback to pre-bipedal hominid locomotion. Nicholas Humphrey, who accompanied the documentary makers, concluded that it was due to a rare set of genetic and developmental circumstances coming together.

The mother recalls that initially all of her 19 children started off walking with a bear-crawl (i.e. on their feet rather than their knees). Second, due to an inherited recessive genetic mutation, they have a non-progressive congenital cerebral ataxia which impairs the balance children normally use to walk bipedally. Without the balance needed to walk bipedally, they perfected in its place their initial bear-crawl into an adult quadruped gait.