Risk factors and clinical profile of autism spectrum disorder in southern Brazil

Intercontinental insights into autism spectrum disorder: a synthesis of environmental influences and DNA methylation

Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disorder characterized by a broad range of symptoms. The etiology of ASD is thought to involve complex gene-environment interactions, which are crucial to understanding its various causes and symptoms. DNA methylation is an epigenetic mechanism that potentially links genetic predispositions to environmental factors in the development of ASD. This review provides a global perspective on ASD, focusing on how DNA methylation studies may reveal gene-environment interactions characteristic of specific geographical regions. It delves into the role of DNA methylation in influencing the causes and prevalence of ASD in regions where environmental influences vary significantly. We also address potential explanations for the high ASD prevalence in North America, considering lifestyle factors, environmental toxins, and diagnostic considerations. Asian and European studies offer insights into endocrine-disrupting compounds, persistent organic pollutants, maternal smoking, and their associations with DNA methylation alterations in ASD. In areas with limited data on DNA methylation and ASD, such as Africa, Oceania, and South America, we discuss prevalent environmental factors based on epidemiological studies. Additionally, the review integrates global and country-specific prevalence data from various studies, providing a comprehensive picture of the variables influencing ASD diagnoses over region and year of assessment. This prevalence data, coupled with regional environmental variables and DNA methylation studies, provides a perspective on the complexities of ASD research. Integrating global prevalence data, we underscore the need for a comprehensive global understanding of ASD's complex etiology. Expanded research into epigenetic mechanisms of ASD is needed, particularly in underrepresented populations and locations, to enhance biomarker development for diagnosis and intervention strategies for ASD that reflect the varied environmental and genetic landscapes worldwide.

Assessment of Knowledge and Attitude of General Practitioners Regarding Autism and Associated Factors at Gondar University Hospital, Gondar, Ethiopia

Background: The neurodevelopmental conditions known as autism spectrum disorders (ASDs) start in early childhood and last the entirety of a person's life. They are characterized by distorted social interaction, difficulties communicating, and repetitive, stereotypical behavior. Objective: This study sought to evaluate general practitioners (GPs)' attitudes and knowledge of ASDs and related factors at Gondar University Hospital. Methods: An institutional-based cross-sectional study design was used. Using a convenience-sample method, three-hundred sixty individuals were chosen for this study. Data were collected using a self-administered questionnaire. The GPs who took part in this survey were characterized by descriptive statistics. The relationship between the dependent variables (knowledge and attitude) and the sociodemographic characteristics was examined using an independent two-sample t-test and Pearson correlation analysis. The Statistical Package for the Social Sciences Version 25 was used for all data analyses. Results: In this study, the GPs had an average age of 31.82 years, with an average of 18 years since graduation and 16 years of practice. Participants' average overall knowledge and attitude scores on autism were 15.83 (SD = 3.27) and 29.54 (SD = 3.21), respectively, both falling within the moderate range. Using an independent t-test, we found a significant difference (p < 0.001) between the attitudes of male and female GPs regarding autism. The study also identified weakly significant correlations between GPs' age and their attitudes toward autism (r = 0.271⁣∗∗, p < 0.001) and between years of practice and attitudes (r = 0.105⁣∗, p=0.046). However, no significant correlations emerged between GPs' knowledge and their age, years since graduation, or years of practice (r = 0.069, p=0.194; r = 0.069, p=0.193; and r = -0.053, p=0.312, respectively). In addition, we observed a weakly significant association (r = 0.004⁣∗∗, p < 0.001) between GPs' knowledge and their attitudes about autism. Conclusion: Based on their total scores, the participants had a moderate level of knowledge and attitudes toward autism. There was a favorable correlation found between the study subjects' attitudes regarding autism and their age, as well as their practice year. Furthermore, a clear correlation was observed between GPs' attitudes and their understanding of autism.

Prevalence of Autism Spectrum Disorder Among Children and Adolescents in the United States from 2021 to 2022

PURPOSE

The prevalence of autism spectrum disorder (ASD) among children and adolescents seem to be high in countries around the world, and it's worth understanding the latest prevalence and trends of ASD in children and adolescents. The purpose of this study was to examine the latest prevalence and decade trend of ASD among individuals aged 3-17 years in the United States.

METHODS

A total of 13,198 individuals aged 3-17 years were included. Annual data were examined from the National Health Interview Survey (2021-2022). Weighted prevalence for each of the selected developmental disabilities were calculated.

RESULTS

This cross-sectional study estimated the weighted prevalence of autism spectrum disorder were 3.05, 3.79, and 3.42% among individuals aged 3-17 years in the US in 2021, 2022, and the 2-year overall, respectively. We also observed a decade-long upward trend even after adjusting for demographic characteristics (P for trend < .05).

CONCLUSION

The results of this study showed that the prevalence of ASD among children and adolescents aged 3-17 years in the United States remained high and has increased over the past decade. The further investigation is necessary to evaluate potential modifiable risk factors and causes of ASD.

Maternal immune activation induces sex-dependent behavioral differences in a rat model of schizophrenia

Background

Maternal immune activation (MIA) is a mature means to construct a schizophrenia model. However, some preclinical studies have reported that a MIA-induced schizophrenia model seemed to have gender heterogeneity in behavioral phenotype. On the other hand, the MIA's paradigms were diverse in different studies, and many details could affect the effect of MIA. To some extent, it is not credible and scientific to directly compare the gender differences of different MIA programs. Therefore, it is necessary to study whether the sex of the exposed offspring leads to behavioral differences on the premise of maintaining a consistent MIA mode.

Methods

An animal model of schizophrenia was established by the administration of 10 mg/kg Poly (I: C) when dams were on day 9 of gestation. Then, a number of female and male offspring completed a series of behavioral tests during postnatal days 61-75.

Results

Compared with the female control group (n = 14), female MIA offspring (n = 12) showed a longer movement distance (d = 1.07, p < 0.05) and higher average speed (d = 1.08, p < 0.05) in the open field test (OFT). In the Y maze test, the percentage of entering the novel arm of female MIA offspring was lower (d = 0.92, p < 0.05). Compared with the male control group (n = 14), male MIA offspring (n = 13) displayed less movement distance (d = 0.93, p < 0.05) and a lower average speed (d = 0.94, p < 0.05) in the OFT. In the Y maze test, the proportion of exploration time in the novel arm of male MIA offspring was lower (d = 0.96, p < 0.05). In the EPM, male MIA offspring showed less time (d = 0.85, p < 0.05) and a lower percentage of time spent in the open arms (d = 0.85, p < 0.05). Male MIA offspring also had a lower PPI index (76 dB + 120 dB, d = 0.81, p < 0.05; 80 dB + 120 dB, d = 1.45, p < 0.01).

Conclusions

Our results showed that the behavioral phenotypes induced by prenatal immune activation were highly dependent on the sex of the offspring.