Featured Research

from universities, journals, and other organizations

Extra Copies Of A Gene Carry Extra Risk

Date:
February 13, 2009
Source:
Weizmann Institute of Science
Summary:
A missing LIS1 gene causes severe mental retardation. New research shows that extra copies ofLIS1 can cause developmental problems, as well.

Is more of a good thing better? A gene known as LIS1 is crucial for ensuring the proper placement of neurons in the developing brain. When an LIS1 gene is missing, brains fail to develop the characteristic folds; babies with lissencephaly or ‘smooth brain’ are born severely mentally retarded.

But new research by Prof. Orly Reiner of the Institute’s Molecular Genetics Department, which recently appeared in Nature Genetics, shows that having extra LIS1 genes can cause problems as well.

Reiner was the first to discover LIS1’s tie to lissencephaly, in 1993. Their latest study shows that it works by helping to determine polarity in the cell – how the various organelles are arranged inside the cell as well as where it connects to neighboring cells. Neurons alter their polarity several times during development, especially when they take on an elongated shape and migrate to new locations in the brain.

But what if, rather than too little, the body has too much LIS1? One of the surprises to come out of the recent spate of post-human-genome research is the number of genes that can be repeated or deleted in an individual’s genome. Most extra copies of genes may be no more harmful than a computer backup disk, but scientists have been finding that some repeats can cause disease.

Research associate Dr. Tamar Sapir and lab technician Talia Levy, working in Reiner’s lab, developed a mouse model in which additional LIS1 protein was produced in the brain. The scientists found that the brains of these mice were a bit smaller than average. On closer inspection, they discovered a range of subtle changes in cell polarity and movement: Nuclei within the proliferating zone tended to move faster, but with less control; rates of cell death were higher; and various factors in the cell became more disordered.

Reiner then asked whether their findings might apply to humans. Together with Jim Lupski and Drs. Weimin Bi and Oleg A. Shchelochkov of Baylor College of Medicine in Houston, Texas, they searched through blood samples using a technique that matches a patient’s DNA with control DNA to identify additions or deletions in its sequence. They identified seven individuals with extra copies of either LIS1 or adjacent genes that are also involved in brain development. All suffered developmental abnormalities. Two of the patients – children with a second LIS1 gene – had previously been diagnosed with failure to thrive and delayed development, and were found to have small brain sizes. A third, who had three copies of the gene, was mentally retarded and suffered from bone deformation as well.

Reiner: ‘Several brain diseases, including schizophrenia, epilepsy and autism, have been linked to faulty neuron migration, and recent research has hinted that some of these may involve variations in gene number. Our study is the first to demonstrate the effects of the duplication of a single gene in a mouse model and tie it to a new ‘copy number variation’ human disease.’

Prof. Orly Reiner’s research is supported by the Nella and Leon Benoziyo Center for Neurological Diseases; the Kekst Family Center for Medical Genetics; the David and Fela Shapell Family Center for Genetic Disorders Research; the PW-Iris Foundation; and the PW- Jani.M Research Fund. Prof. Reiner is the incumbent of the Bernstein-Mason Chair of Neurochemistry.


Story Source:

The above story is based on materials provided by Weizmann Institute of Science. Note: Materials may be edited for content and length.


Journal Reference:

  1. Bi et al. Increased LIS1 expression affects human and mouse brain development. Nature Genetics, 2009; 41 (2): 168 DOI: 10.1038/ng.302

Cite This Page:

Weizmann Institute of Science. "Extra Copies Of A Gene Carry Extra Risk." ScienceDaily. ScienceDaily, 13 February 2009. <www.sciencedaily.com/releases/2009/02/090204101300.htm>.
Weizmann Institute of Science. (2009, February 13). Extra Copies Of A Gene Carry Extra Risk. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2009/02/090204101300.htm
Weizmann Institute of Science. "Extra Copies Of A Gene Carry Extra Risk." ScienceDaily. www.sciencedaily.com/releases/2009/02/090204101300.htm (accessed July 30, 2014).

Share This




More Health & Medicine News

Wednesday, July 30, 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