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.

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 July 29, 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 July 29, 2014).

Share This




More Health & Medicine News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Generics Eat Into Pfizer's Sales

Generics Eat Into Pfizer's Sales

Reuters - Business Video Online (July 29, 2014) — Pfizer, the world's largest drug maker, cut full-year revenue forecasts because generics could cut into sales of its anti-arthritis drug, Celebrex. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Nigeria Ups Ebola Stakes on 1st Death

Nigeria Ups Ebola Stakes on 1st Death

Reuters - Business Video Online (July 29, 2014) — Nigerian authorities have shut and quarantined a Lagos hospital where a Liberian man died of the Ebola virus, the first recorded case of the highly-infectious disease in Africa's most populous economy. David Pollard reports Video provided by Reuters
Powered by NewsLook.com
Running 5 Minutes A Day Might Add Years To Your Life

Running 5 Minutes A Day Might Add Years To Your Life

Newsy (July 29, 2014) — According to a new study, just five minutes of running or jogging a day could add years to your life. Video provided by Newsy
Powered by NewsLook.com
Ebola Outbreak Poses Little Threat To U.S.: CDC

Ebola Outbreak Poses Little Threat To U.S.: CDC

Newsy (July 29, 2014) — The Ebola outbreak in West Africa poses little threat to Americans, according to officials with the Centers for Disease Control and Prevention. 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:
from the past week

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