RCMG will continue to study the genetic basis of schizophrenia pathogenesis of as part of a grant from the Russian Science Foundation

According to the WHO, schizophrenia is one of the ten main causes of disability, with 60% of patients becoming disabled and 90% of patients having an unstable work adaptation. According to statistics, the schizophrenia incidence in the Russian Federation is 6.5 per 100,000 people. Scientists around the world have been trying to find a solution to the mystery of schizophrenia. In recent decades, the world scientific literature regularly publishes information about the role of multiple genes in the etiology and pathogenesis of the disease. Almost all authors consider only unique or low-copy genes, i.e. those represented in the genome in small numbers of copies. However, two-thirds of human DNA contains repetitive sequences, and these repeats play a major role in cellular function.

Researchers at the RCMG Molecular Biology Laboratory have for the first time drawn attention to tandem repeats in the genomes of schizophrenia patients. These repeats relate to the genome understudied regions. Repeats are the same DNA sequences that are duplicated several times, and can be located on a single chromosome or on multiple ones. Today, the telomere repeat is the most studied among the tandem repeats. It has been shown that the number of its copies decreases with aging, oxidative stress and pathology.

Conventional methods such as sequencing and PCR cannot identify the number of copies of repeats in the genome. The RCMG Molecular Biology Laboratory has developed a unique method that allowed determining the content of tandem repeats in the genome on a large number of human DNA samples. For the first time, the content of two tandem repeats - ribosomal and satellite III repeats (Sat III) - was determined in large samples (1770 individuals).

“Under the previous grant, we examined a group of schizophrenia patients whose treatment was successful and they went into remission. Now, we will focus on the group in which therapy did not bring any expected result”, Svetlana Kostyuk, head of the Molecular Biology Laboratory, said. “The method involves joint identification of four indicators in the same sample of isolated cell DNA: rDNA copy number, SatIII content, telomere repeat (TR) and DNA oxidation marker (8-oxodG). We are focusing on basic research, but it will have practical implication - based on these data we intend to create a methodology that will allow clinicians to predict the effectiveness of schizophrenia treatment using the genomic repeats analysis.”

Grant number is 18-15-00437-P “Role of ribosomal genes in the etiology and pathogenesis of schizophrenia. Prognostic value of properties of a patient's ribosomal gene complex in response to schizophrenia therapy.”