Clinical characteristics of familial schizophrenia

Correlation of rs35753505 polymorphism in Neuregulin 1 gene with psychopathology and intelligence of people with schizophrenia

BACKGROUND AND AIM

Schizophrenia is one of the most severe psychiatric disorders. About 0.5 to 1% of the world's population suffers from this non-Mendelian disorder. Environmental and genetic factors seem to be involved in this disorder. In this article, we investigate the alleles and genotypic correlation of mononucleotide rs35753505 polymorphism of Neuregulin 1 (NRG1), one of the selected genes of schizophrenia, with psychopathology and intelligence.

MATERIALS AND METHODS

102 independent and 98 healthy patients participated in this study. DNA was extracted by the salting out method and the polymorphism (rs35753505) were amplified by polymerase chain reaction (PCR). Sanger sequencing was performed on PCR products. Allele frequency analysis was performed using COCAPHASE software, and genotype analysis was performed using Clump22 software.

RESULTS

According to our study's statistical findings, all case samples from the three categories of men, women, and overall participants significantly differed from the control group in terms of the prevalence of allele C and the CC risk genotype. The rs35753505 polymorphism significantly raised Positive and Negative Syndrome Scale (PANSS) test results, according to a correlation analysis between the two variables. However, this polymorphism led to a significant decrease in overall intelligence in case samples compared to control samples.

CONCLUSION

In this study, it seems that the rs35753505 polymorphism of NRG1 gene has a significant role in the sample of patients with schizophrenia in Iran and also in psychopathology and intelligence disorders.

Brain-gut axis and psychiatric disorders: A perspective from bibliometric and visual analysis

BACKGROUND

The Brain-Gut Axis, a bidirectional signaling pathway that connects the intestinal and central nervous systems, plays an important role in the development of psychiatric disorders. However, the overall research trends in this field are unclear. This study explored the patterns of research on the brain-gut axis and psychiatric disorders from a bibliometric perspective.

METHODS

Relevant data were retrieved from the Web of Science Core Collection, with search terms on psychiatric disorders and the brain-gut axis. R (version 4.2.0), VOSviewer (version 1.6.17), CiteSpace software, and the online bibliometric platform were used in the data analysis.

RESULTS

A total of 2,298 articles published between 1993 and 2022 were identified, showing an increasing trend over time. China (1,859; 20.70%) was the country that contributed the most publications. The journal Nutrients (95; 4.13%) published the most publications. Cryan JF (153; H-index=73) and University College Cork (559; 22.54%) were the most influential author and the most productive institution, respectively. The high-frequency keywords were clustered into six themes, including neurodegenerative diseases, stress-related diseases, immune, brain behavior, depression, and probiotic-related topics; of which, depression (880; 2019), anxiety (207; 2018) and autism (191; 2019) were the most studied psychiatric disorders in the past 5 years. "Depressive symptom" (2019-2020) and "probiotic treatment" (2019-2020) were the main areas addressed in recent years.

CONCLUSION

Research on the brain-gut axis and psychiatric disorders has attracted increasing attention in the past decade, with most publications originating from high-income level countries. This study provides a useful perspective on understanding the research trends, key hot topics, and research gaps in this expanding field.