Featured Research

from universities, journals, and other organizations

Genetic Mutation Linked To Walking On All Fours

Date:
June 4, 2008
Source:
European Society of Human Genetics
Summary:
What are the genes implicated in upright walking of humans? The discovery of four families in which some members only walk on all fours may help us understand how humans, unlike other primates, are able to walk for long periods on only two legs.

While normal infants make the transition to walking on two legs in a relatively short period, some members of a recently discovered group of families continued to move on their palms and feet and never walked upright.
Credit: iStockphoto/Eugeny Shevchenko

What are the genes implicated in upright walking of humans? The discovery of four families in which some members only walk on all fours (quadrupedality) may help us understand how humans, unlike other primates, are able to walk for long periods on only two legs, a scientist will tell the annual conference of the European Society of Human Genetics on June 2.

Related Articles


The quadrupedal families in Turkey previously attracted attention in 2005, when they were discovered. Now the Turkish team reports that they have found the first gene implicated in quadrupedal locomotion in these families.

Professor Tayfun Ozcelik, of Bilkent University, Ankara, Turkey, and colleagues, studied four unrelated families where some members were affected by the rare quadrupedic condition, Unertan syndrome, which is also associated with imperfect articulation of speech, mental retardation, and defects in the cerebellum, a part of the brain involved in motor control. They found that the affected individuals in two families had mutations in the gene responsible for the expression of very low density lipoprotein receptor (VLDLR), a protein which is known to be critical to the proper functioning of the cerebellum during development.

Although the families lived in isolated villages 200-300 km apart and reported no ancestral relationships, the scientists expected to find a single genetic mutation implicated in the condition. They were surprised to find that this was not the case.

"We carried out genome-wide screening on these families", said Professor Ozcelik, "and found regions of DNA that were shared by all those family members who walk on all fours. However, we were surprised to find that genes on three different chromosomes are responsible for the condition in four different families.

"In families A and D there were mutations in VLDLR on chromosome 9, and in family B the phenotype maps to chromosome 17 to a region that contains at least 157 genes, and we are still looking for the precise mutation. Neither region appears to be implicated for family C."

In all cases, the affected individuals were the offspring of consanguineous marriages, which suggests that if they had married outside the family they would not have had the condition. All of them had significant developmental delay in infancy. "Whereas normal infants make the transition to walking on two legs in a relatively short period", said Professor Ozcelik, "these individuals continued to move on their palms and feet and never walked upright. Although they can stand from a sitting position and maintain this upright position with flexed hips and knees, they virtually never initiate bipedal walking on their own."

It has been suggested in the past that lack of access to medical care exacerbated the effects of an under-developed cerebellum, and that this led to quadrupedality. "Although it may be true that family B lacked proper medical care, families A and D had consistent access to good medical attention, and both families sought a correction of quadrupedality in their affected children", said Professor Ozcelik. "Indeed, an unaffected member of family A is a physician, who has been actively involved in the medical interventions. In addition, the parents in family A also discouraged their affected children from walking on all fours, to no avail. We think that social factors are unlikely to be involved in the development of quadrupedal locomotion."

Mutations causing VLDLR deficiency are also found in Hutterites, a group of Anabaptists who live in colonies of North America. There, however, most of the affected individuals cannot walk at all. The neurological characteristics of the affected members of the Turkish families and the Hutterites seem similar, with the most striking difference being that the Turkish individuals are able to walk on all fours, said the scientists. They hypothesize that the Hutterites may be more profoundly affected due to the deficiency in VLDLR and a neighbouring gene, and therefore lack the motor skills even for quadrupedal locomotion.

Along with brain enlargement, speech, and the ability to make tools, upright walking has long been regarded as one of the key traits that have led to modern humans. Professor Ozcelik's team have opened a window on how mutations in VLDLR affect brain development and influence gait in humans.

"It will be interesting to see if the VLDLR gene is involved in other types of cerebellar ataxias. In addition, we hope to identify the defective genes associated with quadrupedal locomotion in families B and C", he says.

Through grants from the Scientific and Technological Research Council of Turkey in Ankara, and the International Centre for Genetic Engineering and Biotechnology in Trieste, Italy, Professor Ozcelik and his colleagues are currently screening the remaining families for mutations.


Story Source:

The above story is based on materials provided by European Society of Human Genetics. Note: Materials may be edited for content and length.


Cite This Page:

European Society of Human Genetics. "Genetic Mutation Linked To Walking On All Fours." ScienceDaily. ScienceDaily, 4 June 2008. <www.sciencedaily.com/releases/2008/06/080602075844.htm>.
European Society of Human Genetics. (2008, June 4). Genetic Mutation Linked To Walking On All Fours. ScienceDaily. Retrieved March 5, 2015 from www.sciencedaily.com/releases/2008/06/080602075844.htm
European Society of Human Genetics. "Genetic Mutation Linked To Walking On All Fours." ScienceDaily. www.sciencedaily.com/releases/2008/06/080602075844.htm (accessed March 5, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Thursday, March 5, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Bupa Eyes India Healthcare Opportunities

Bupa Eyes India Healthcare Opportunities

Reuters - Business Video Online (Mar. 5, 2015) — Bupa is hoping to expand in India&apos;s fast-growing health insurance market, once a rule change on foreign investment is implemented. The British private healthcare group&apos;s CEO tells Grace Pascoe why it&apos;s so keen on the new opportunity. Video provided by Reuters
Powered by NewsLook.com
Doctor in Your Pocket Is Getting Smarter

Doctor in Your Pocket Is Getting Smarter

Reuters - Business Video Online (Mar. 5, 2015) — Mobile apps are turning smartphones into a personal doctors, with users able to measure heart rate, blood pressure and even blood sugar. But will it change our behaviour? Ivor Bennett reports from the Mobile World Congress in Barcelona. Video provided by Reuters
Powered by NewsLook.com
AbbVie Inks $21B Deal To Buy Cancer Drugmaker Pharmacyclics

AbbVie Inks $21B Deal To Buy Cancer Drugmaker Pharmacyclics

Newsy (Mar. 5, 2015) — AbbVie announced Wednesday it will buy cancer drugmaker Pharmacyclics in a $21 billion deal. Video provided by Newsy
Powered by NewsLook.com
Adults Only Get The Flu Twice A Decade, Researchers Say

Adults Only Get The Flu Twice A Decade, Researchers Say

Newsy (Mar. 4, 2015) — Researchers found adults only get the flu about once every five years. Scientists analyzed how a person&apos;s immunity builds up over time as well. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins