Featured Research

from universities, journals, and other organizations

Scientists link evolved, mutated gene module to syndromic autism

Date:
January 27, 2012
Source:
University of California - San Diego
Summary:
Medical researchers reports that newly discovered mutations in an evolved assembly of genes cause Joubert syndrome, a form of syndromic autism.

Image using an electron microscope shows a cilium growing from a neuron.
Credit: Gleeson lab, UC San Diego

A team led by researchers at the University of California, San Diego School of Medicine reports that newly discovered mutations in an evolved assembly of genes cause Joubert syndrome, a form of syndromic autism.

Related Articles


The findings are published in the January 26 online issue of Science Express.

Joubert syndrome is a rare, recessive brain condition characterized by malformation or underdevelopment of the cerebellum and brainstem. The disease is due specifically to alterations in cellular primary cilia -- antenna-like structures found on most cells. The consequence is a range of distinct physical and cognitive disabilities, including poor muscle control, and mental retardation. Up to 40 percent of Joubert syndrome patients meet clinical criteria for autism, as well as other neurocognitive disorders, so it is considered a syndromic form of autism.

The cause or causes of Joubert syndrome are not well-understood. Researchers looked at mutations in the TMEM216 gene, which had previously been linked to the syndrome. However, only half of the expected Joubert syndrome patients exhibit TMEM216 gene mutations; the other half did not. Using genomic sequencing, the research team, led by Joseph G. Gleeson, MD, professor of neurosciences and pediatrics at UC San Diego, broadened their inquiry and discovered a second culprit: mutations in a neighboring gene called TMEM138.

"It is extraordinarily rare for two adjacent genes to cause the same human disease," said Gleeson. "The mystery that emerged from this was whether these two adjacent, non-duplicated genes causing indistinguishable disease have functional connections at the gene or protein level."

Through evolutionary analysis, the scientists concluded that the two TMEM genes became joined end-to-end approximately 260 million years ago, about the time some amphibians began transitioning into land-based reptiles. The connected genes evolved in tandem, becoming regulated by the same transcription factors.

"Prior to this transition, the two genes had wildly different expression levels," said Jeong Ho Lee, MD, PhD, and first author of the study. "Following this transition, they became tightly co-regulated. Moreover, we found that the two encoded proteins coordinate delivery of factors key for cilia assembly."

Gleeson said the findings suggest the human genome has evolved to take advantage of fortuitous ancestral events like gene translocations to better coordinate gene expression by assembling into specific modules. When these modules are disrupted, however, neurodevelopmental diseases may result.

This research was funded, in part, by the Simons Foundation, the American Philosophical Society, the National Institutes of Health and the Howard Hughes Medical Institute.


Story Source:

The above story is based on materials provided by University of California - San Diego. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jeong Ho Lee, Jennifer L. Silhavy, Ji Eun Lee, Lihadh Al-Gazali, Sophie Thomas, Erica E. Davis, Stephanie L. Bielas, Kiley J. Hill, Miriam Iannicelli, Francesco Brancati, Stacey B. Gabriel, Carsten Russ, Clare V. Logan, Saghira Malik Sharif, Christopher P. Bennett, Masumi Abe, Friedhelm Hildebrandt, Bill H. Diplas, Tania Attiι-Bitach, Nicholas Katsanis, Anna Rajab, Roshan Koul, Laszlo Sztriha, Elizabeth R. Waters, Susan Ferro-Novick, Geoffrey C. Woods, Colin A. Johnson, Enza Maria Valente, Maha S. Zaki, and Joseph G. Gleeson. Evolutionarily Assembled cis-Regulatory Module at a Human Ciliopathy Locus. Science, 26 January 2012 DOI: 10.1126/science.1213506

Cite This Page:

University of California - San Diego. "Scientists link evolved, mutated gene module to syndromic autism." ScienceDaily. ScienceDaily, 27 January 2012. <www.sciencedaily.com/releases/2012/01/120126143651.htm>.
University of California - San Diego. (2012, January 27). Scientists link evolved, mutated gene module to syndromic autism. ScienceDaily. Retrieved October 24, 2014 from www.sciencedaily.com/releases/2012/01/120126143651.htm
University of California - San Diego. "Scientists link evolved, mutated gene module to syndromic autism." ScienceDaily. www.sciencedaily.com/releases/2012/01/120126143651.htm (accessed October 24, 2014).

Share This



More Health & Medicine News

Friday, October 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) — IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) — A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
WHO: Millions of Ebola Vaccine Doses by 2015

WHO: Millions of Ebola Vaccine Doses by 2015

AP (Oct. 24, 2014) — The World Health Organization said on Friday that millions of doses of two experimental Ebola vaccines could be ready for use in 2015 and five more experimental vaccines would start being tested in March. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Doctor in NYC Quarantined With Ebola

Doctor in NYC Quarantined With Ebola

AP (Oct. 24, 2014) — An emergency room doctor who recently returned to the city after treating Ebola patients in West Africa has tested positive for the virus. He's quarantined in a hospital. (Oct. 24) Video provided by AP
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