Schizophrenia: Researchers discover genetic changes in those affected
The causes of the development of schizophrenia are still largely unclear. Scientists at Heidelberg University Hospital have now reported that "ten previously unknown gene changes (mutations) have been discovered in schizophrenia patients", which can be assessed as risk factors for schizophrenic diseases. The results of the research team led by first author Dr. Slavil Peykov were published in the renowned journal "Molecular Psychiatry", according to the announcement of the university hospital.
According to the researchers, around one percent of the world's population suffers from the mental disorder schizophrenia, with the disease usually occurring in early adulthood. Those affected are hardly able to cope with their everyday life independently during the flare-ups and occasionally beyond, reports the university hospital. They suffer from perceptual disorders such as delusions or hallucinations, often accompanied by language problems and depression. Overall, the symptoms of schizophrenia can vary widely, which can make diagnosis and treatment significantly more difficult.
Gene variants as risk factors for schizophrenia To date, little is known about the exact causes and triggers of schizophrenia, according to the Heidelberg University Hospital. With their current study, the researchers led by Dr. Slavil Peykov has now discovered ten previously unknown genetic changes that are obviously related to the development of schizophrenia. "These ten gene variants represent risk factors for a schizophrenic disease," emphasizes the director of the Molecular Human Genetics Department at Heidelberg University Hospital, Prof. Dr. Gudrun Rappold. The affected gene provides the blueprint for a scaffold protein - the so-called SHANK2 protein - which plays a crucial role in the signal transmission between nerve cells. Since the changes only occurred in patients, but not in healthy controls, the researchers became aware of the ten previously unknown mutations.
Schizophrenia patients increasingly show genetic changes "Mutations that are not found in healthy people could have a direct impact on the disease," explains Dr. Slavil Peykov. The Heidelberg researchers, in collaboration with Professor Marcella Rietschel from the Department of Genetic Epidemiology at the Central Institute for Mental Health in Mannheim and Professor Markus Noethen from the Institute of Human Genetics at the University of Bonn, examined the SHANK2 gene in the genome of 481 patients and 659 healthy controls. Overall, schizophrenia patients had genetic changes about twice as often as people without mental illness, reports the university hospital. Some of the gene variants are clear risk factors, although the disease will probably only start "if other factors, such as certain environmental influences, are added," explains human geneticist Prof. Gudrun Rappold.
Changes in the same gene also for autism As early as 2010, scientists led by human geneticist Rappold "had detected various changes in the SHANK2 gene in patients with autistic disorder and intellectual disabilities," reports the Heidelberg University Hospital. The mutations now found in schizophrenia would lie in the same gene, but would differ significantly from the changes in autism. "Obviously, the exact nature of the change affects which neuropsychiatric disease develops and how severe the symptoms are," explains Rappold. For example, “Changes in one and the same gene could lead to very different neurobiological diseases such as autism and schizophrenia or to intellectual disabilities.” All these mutations have in common that they affect the degree of cross-linking of certain areas of the nerve cells to different degrees and thus also the signal transmission between the nerve cells affect.
Advantages for the treatment of schizophrenia patients The development of the disease cannot be explained by the determination of further genetic risk factors for schizophrenia. But "knowing the genetic causes of this disease can help doctors in the future to divide those affected into subgroups with a similar course of the disease and to treat them more specifically at an early stage," explains the human geneticist Rappold. For example, there were four unrelated patients among the 481 patients who had exactly the same mutations. "They started the disease comparatively early and with similar symptoms," said the university hospital. The search for the genetic background also brings advantages in the development of new therapies. "If it is known which molecular processes in the brain are disturbed, scientists can research new therapeutic approaches in a more targeted manner," reports the Heidelberg University Hospital. (fp)
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