Featured Research

from universities, journals, and other organizations

Schizophrenia: Gathering clues to rare gene variants contributing to disease

Date:
February 20, 2014
Source:
Elsevier
Summary:
Schizophrenia has long been known to be highly heritable and is present in approximately 1% of the population. Researchers have been following two paths in their pursuit of identifying schizophrenia risk genes. Initially, they studied common gene variants that, individually, only increase the risk for schizophrenia by a few percent, perhaps increasing the likelihood of developing schizophrenia from a 10 out of a 1000 chance to an 11 or 12 out of a 1000 chance. More recently, research has identified gene variants that are rare in the population but, when present, more substantially increase the risk for developing schizophrenia. Results have been recently published in two new articles.

Schizophrenia has long been known to be highly heritable and is present in approximately 1% of the population. Researchers have been following two paths in their pursuit of identifying schizophrenia risk genes.

Initially, they studied common gene variants that, individually, only increase the risk for schizophrenia by a few percent, perhaps increasing the likelihood of developing schizophrenia from a 10 out of a 1000 chance to an 11 or 12 out of a 1000 chance.

More recently, research has identified gene variants that are rare in the population but, when present, more substantially increase the risk for developing schizophrenia. For example, in the current issue of Biological Psychiatry, a large collaborating group of international scientists, led by Dr. Jennifer Mulle, an Assistant Professor at Emory, report a 1.4 megabase duplication on chromosome 7 (7q11.23) that increases the risk for schizophrenia over 10 times, i.e., to 100 out of a 1000 chance (10%).

"We also found it interesting that three different disorders (schizophrenia, autism, and intellectual development) that strike at different times and present in different ways, have genetic links to this same region on chromosome 7," commented Mulle. "Our findings support the notion of a neuro-developmental link between these disorders."

In this same issue, Dr. George Kirov at Cardiff University and colleagues scanned the genome for copy number gene variants, i.e., where abnormal numbers of gene copies exist. They studied 70 of these variants, all previously implicated in schizophrenia and/or early-onset developmental disorders, such as developmental delay, intellectual deficit and autism spectrum disorders (DD/ID/ASD). They then compared the risk for carriers of these variants to develop one or more of these disorders, i.e. their genetic penetrance.

"The result might be unexpected for many: the penetrance for schizophrenia is several times lower than for the group of DD/ID/ASD. The total penetrance for any of these disorders is quite high, ranging from 10% for duplications at 16p13.11 to nearly 100% for the velocardiofacial syndrome region on chromosome 22. These findings will have implications for genetic counselling of carriers," said Kirov.

"It seems that we are at a critical point in the genetics of schizophrenia -- the identification of rare gene variants that substantially increase the risk for schizophrenia," said Dr. John Krystal, Editor of Biological Psychiatry. "However, we have a very limited understanding of how these genes alter brain development to produce schizophrenia and other disorders. This knowledge would seem to hold clues about mechanisms of prevention and treatment."

In addition, scientists do not yet understand why the genetics of schizophrenia is not tightly aligned with the symptoms of schizophrenia. In other words, gene variants that increase the risk for schizophrenia increase the risk for other disorders, such as developmental delay, autism, and bipolar disorder.

"The failure of our genome to follow DSM-V is not simply a shortcoming of our diagnostic manual, rather it is yet another reminder that there are fundamental aspects of the biology of psychiatric disorders that we do not understand," added Krystal.


Story Source:

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


Journal References:

  1. Jennifer Gladys Mulle, Ann E. Pulver, John A. McGrath, Paula S. Wolyniec, Anne F. Dodd, David J. Cutler, Jonathan Sebat, Dheeraj Malhotra, Gerald Nestadt, Donald F. Conrad, Matthew Hurles, Chris P. Barnes, Masashi Ikeda, Nakao Iwata, Douglas F. Levinson, Pablo V. Gejman, Alan R. Sanders, Jubao Duan, Adele A. Mitchell, Inga Peter, Pamela Sklar, Colm T. O’Dushlaine, Detelina Grozeva, Michael C. O’Donovan, Michael J. Owen, Christina M. Hultman, Anna K. Kδhler, Patrick F. Sullivan, George Kirov, Stephen T. Warren. Reciprocal Duplication of the Williams-Beuren Syndrome Deletion on Chromosome 7q11.23 Is Associated with Schizophrenia. Biological Psychiatry, 2014; 75 (5): 371 DOI: 10.1016/j.biopsych.2013.05.040
  2. George Kirov, Elliott Rees, James T.R. Walters, Valentina Escott-Price, Lyudmila Georgieva, Alexander L. Richards, Kimberly D. Chambert, Gerwyn Davies, Sophie E. Legge, Jennifer L. Moran, Steven A. McCarroll, Michael C. O’Donovan, Michael J. Owen. The Penetrance of Copy Number Variations for Schizophrenia and Developmental Delay. Biological Psychiatry, 2014; 75 (5): 378 DOI: 10.1016/j.biopsych.2013.07.022

Cite This Page:

Elsevier. "Schizophrenia: Gathering clues to rare gene variants contributing to disease." ScienceDaily. ScienceDaily, 20 February 2014. <www.sciencedaily.com/releases/2014/02/140220083151.htm>.
Elsevier. (2014, February 20). Schizophrenia: Gathering clues to rare gene variants contributing to disease. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2014/02/140220083151.htm
Elsevier. "Schizophrenia: Gathering clues to rare gene variants contributing to disease." ScienceDaily. www.sciencedaily.com/releases/2014/02/140220083151.htm (accessed October 23, 2014).

Share This



More Mind & Brain News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Working Mother Getaway: Beaches Turks & Caicos

Working Mother Getaway: Beaches Turks & Caicos

Working Mother (Oct. 22, 2014) — Feast your eyes on this gorgeous family-friendly resort. Video provided by Working Mother
Powered by NewsLook.com
What Your Favorite Color Says About You

What Your Favorite Color Says About You

Buzz60 (Oct. 22, 2014) — We all have one color we love to wear, and believe it or not, your color preference may reveal some of your character traits. In celebration of National Color Day, Krystin Goodwin (@kyrstingoodwin) highlights what your favorite colors may say about you. Video provided by Buzz60
Powered by NewsLook.com
First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

Newsy (Oct. 21, 2014) — A medical team has for the first time given a man the ability to walk again after transplanting cells from his brain onto his severed spinal cord. Video provided by Newsy
Powered by NewsLook.com
Portable Breathalyzer Gets You Home Safely

Portable Breathalyzer Gets You Home Safely

Buzz60 (Oct. 21, 2014) — Breeze, a portable breathalyzer, gets you home safely by instantly showing your blood alcohol content, and with one tap, lets you call an Uber, a cab or a friend from your contact list to pick you up. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
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