Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers identify dozens of new de novo genetic mutations in schizophrenia

04.10.2012
Many newly discovered genes most active during fetal development

Columbia University Medical Center (CUMC) researchers have identified dozens of new spontaneous genetic mutations that play a significant role in the development of schizophrenia, adding to the growing list of genetic variants that can contribute to the disease. The study, the largest and most comprehensive of its kind, was published today in the online edition of the journal Nature Genetics.

Although schizophrenia typically onsets during adolescence and early adulthood, many of the mutations were found to affect genes with higher expression during early-to-mid fetal development. Together, the findings show that both the function of the mutated gene and when the gene is expressed are critically important in determining the risk for schizophrenia.

The findings inform epidemiologic studies showing that environmental factors, such as malnutrition or infections during pregnancy, can contribute to the development of schizophrenia. "Our findings provide a mechanism that could explain how prenatal environmental insults during the first and second trimester of pregnancy increase one's risk for schizophrenia," said study leader Maria Karayiorgou, MD, professor of psychiatry at CUMC, and acting chief, division of Psychiatric and Medical Genetics, New York State Psychiatric Institute. "Patients with these mutations were much more likely to have had behavioral abnormalities, such as phobias and anxiety in childhood, as well as worse disease outcome."

In an earlier study of 53 families, the team of investigators found that spontaneous, or de novo, mutations — genetic errors that are present in patients but not in their parents — play a role in a substantial portion of sporadic cases of schizophrenia. The mutations were found in the part of the genome that codes for proteins, known as the exome.

In the larger, current study, the researchers performed whole-exome sequencing on 231 patient "trios" from the United States and South Africa. Each trio consisted of a patient and both of his or her parents, who were unaffected by the disease. By comparing the exomes of the patients with those of their parents, the researchers were able to identify de novo rather than heritable, mutations that may contribute to schizophrenia. This is the first study of this scale to search for single nucleotide variations in the exomes of schizophrenia patients. Previous studies from the Columbia group and others searched for much larger genetic variations, such as gene deletions or duplications.

The researchers identified many mutated genes with diverse functions. They also identified four new genes (LAMA2, DPYD, TRRAP, and VPS39) affected by recurrent de novo events within or across the two populations, a finding unlikely to have occurred by chance.

The researchers estimate that several hundred loci (genetic locations) can contribute to the development of schizophrenia. "The chance that two patients have exactly the same mutation or combination of mutations is rather small" said Dr. Karayiorgou. "What is intriguing is that despite this variability, people with schizophrenia tend to have, more or less, the same phenotype—that is, the same clinical presentation. Our hypothesis is that many neural circuits are extremely important in schizophrenia and that these circuits are vulnerable to a number of influences. So, when any of the genes involved in these circuits are mutated, the end result is the same."

According to the researchers, the challenge remains to identify the affected biological processes and neural circuits, and to determine how they are affected.

"Although the genetics of schizophrenia are extremely complex, a coherent picture of the disease is beginning to emerge," said co-director of the study Dr. Joseph Gogos, MD, PhD, and associate professor of physiology and neuroscience at Columbia University Medical Center. "Our studies show that dozens, and perhaps hundreds, of different spontaneous mutations can raise one's risk for schizophrenia. On the surface, this is daunting, but using these new findings to understand how these mutations affect the same neural circuits, including during early fetal development, raises hopes that it may be possible to develop effective prevention and treatment strategies for the disease."

The paper is titled, "De novo gene mutations highlight patterns of genetic and neural complexity in schizophrenia." The other contributors are Bin Xu (CUMC), Iuliana Ionita-Laza (CUMC), J. Louw Roos (University of Pretoria, Pretoria, South Africa), Braden Boone (Hudson Alpha Institute for Biotechnology, Huntsville, Ala.), Scarlet Woodrick (CUMC), Yan Sun (CUMC) and Shawn Levy (Hudson Alpha Institute for Biotechnology).

The research was partially supported by National Institute of Mental Health grants MH061399 and MH077235 and the Lieber Center for Schizophrenia Research at Columbia University.

The authors declare no financial conflict of interest.

About Schizophrenia

Contrary to popular belief, schizophrenia is not a split personality; it is a chronic, severe, and disabling brain disorder that affects just over one percent of the adult population and is characterized by loss of contact with reality (psychosis), hallucinations (usually, hearing voices), firmly held false beliefs (delusions), abnormal thinking, a restricted range of emotions (flattened affect) or inappropriate and disorganized behavior, social withdrawal, and diminished motivation.

The disease often strikes in the early adult years, and although many individuals experience some recovery, many others experience substantial and lifelong disability. People with schizophrenia often have problems functioning in society and in relationships and are over-represented on disability rolls and among the homeless and imprisoned.

The precise causes of schizophrenia are not known, but current research suggests a combination of hereditary and environmental factors. Fundamentally, however, it is a biologic problem (involving changes in the brain), not one caused by poor parenting or a mentally unhealthy environment.

Since the causes of schizophrenia are not clear, treatments focus on eliminating disease symptoms. Treatments include antipsychotic medications and various psychosocial treatments.

Columbia University Medical Center provides international leadership in basic, pre-clinical and clinical research, in medical and health sciences education, and in patient care. The medical center trains future leaders and includes the dedicated work of many physicians, scientists, public health professionals, dentists, and nurses at the College of Physicians and Surgeons, the Mailman School of Public Health, the College of Dental Medicine, the School of Nursing, the biomedical departments of the Graduate School of Arts and Sciences, and allied research centers and institutions. Established in 1767, Columbia's College of Physicians and Surgeons was the first institution in the country to grant the M.D. degree and is among the most selective medical schools in the country. Columbia University Medical Center is home to the largest medical research enterprise in New York City and State and one of the largest in the United States. www.cumc.columbia.edu

Columbia Psychiatry is ranked among the best departments and psychiatric research facilities in the Nation and has contributed greatly to the understanding of and current treatment for psychiatric disorders. Located at the New York State Psychiatric Institute on the NewYork-Presbyterian Hospital/Columbia University Medical Center campus in the Washington Heights community of Upper Manhattan, the department enjoys a rich and productive collaborative relationship with physicians in various disciplines at Columbia University's College of Physicians and Surgeons. Columbia Psychiatry is home to distinguished clinicians and researchers noted for their clinical and research advances in the diagnosis and treatment of depression, suicide, schizophrenia, bipolar and anxiety disorders, and childhood psychiatric disorders. http://columbiapsychiatry.org/

Karin Eskenazi | EurekAlert!
Further information:
http://www.columbia.edu

More articles from Life Sciences:

nachricht Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz

nachricht Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>