The scientists found that deletions and duplications of DNA are more common in people with the mental disorder, and that many of those errors occur in genes related to brain development and neurological function. The findings, which were replicated by a team at the National Institute of Mental Health, appear in the March 27 online edition of the journal Science.
Schizophrenia, a debilitating psychiatric disorder, affects approximately 1 percent of the population. People with schizophrenia suffer from hallucinations, delusions, and disorganized thinking, and are at risk for unusual or bizarre behaviors. The illness greatly impacts social and occupational functioning and has enormous public health costs.
The team of investigators, led by Tom Walsh, Jon McClellan, and Mary-Claire King at the UW, and Shane McCarthy and Jonathan Sebat at Cold Spring Harbor, examined whether the genetic errors, which are individually rare DNA deletions and duplications, contribute to the development of schizophrenia.
Some deletions and duplications are common and found in all humans. The researchers studied such mutations that were found only in individuals with the illness, and compared them to mutations found only in healthy persons. They theorized that rare mutations found only in schizophrenic patients would be more likely to disrupt genes related to brain functioning and thus may cause schizophrenia.
The study was conducted using DNA from 150 people with schizophrenia and 268 healthy individuals. The investigators found rare deletions and duplications of genes present in 15 percent of those with schizophrenia, versus only 5 percent in the healthy controls. The rate was even higher in patients whose schizophrenia first presented at a younger age, with 20 percent of those patients having a rare mutation.
The results were replicated by a second research team, led by Anjene Addington and Judith Rapoport at the National Institutes of Mental Health. They found a higher rate of rare duplications or deletions in patients whose schizophrenia began before age 12 years, a very rare and severe form of the disorder.
In individuals with schizophrenia, mutations were more likely to disrupt signaling genes that help organize brain development. Each mutation was different, and impacted different genes. However, several of the disrupted genes function in related neurobiological pathways.
The findings suggest that schizophrenia is caused by many different mutations in many different genes, with each mutation leading to a disruption in key pathways important to a developing brain. Once a disease-causing mutation is identified, other different disease-causing mutations may be found in the same gene in different people with the illness.
Thus, for most cases of schizophrenia, the genetic causes may be different. This observation has important implications for schizophrenia research. Currently, most genetic studies examine for mutations that are shared among different individuals with the illness. These approaches will not work if most patients have different mutations causing their condition.
Fortunately, there are now genomic technologies available that allow researchers to discover rare mutations within each individual with a disorder. As these technologies improve, it will be possible to detect other types of disease-causing mutations. Eventually, the identification of genes disrupted in individuals with schizophrenia will allow the development of new treatments more specifically targeted to disrupted pathways.
Justin Reedy | EurekAlert!
Transport of molecular motors into cilia
28.03.2017 | Aarhus University
Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
29.03.2017 | Materials Sciences
29.03.2017 | Physics and Astronomy
29.03.2017 | Earth Sciences