scholarly journals Genetic and Epigenetic Etiology Underlying Autism Spectrum Disorder

2020 ◽  
Vol 9 (4) ◽  
pp. 966 ◽  
Author(s):  
Sang Hoon Yoon ◽  
Joonhyuk Choi ◽  
Won Ji Lee ◽  
Jeong Tae Do

Autism spectrum disorder (ASD) is a pervasive neurodevelopmental disorder characterized by difficulties in social interaction, language development delays, repeated body movements, and markedly deteriorated activities and interests. Environmental factors, such as viral infection, parental age, and zinc deficiency, can be plausible contributors to ASD susceptibility. As ASD is highly heritable, genetic risk factors involved in neurodevelopment, neural communication, and social interaction provide important clues in explaining the etiology of ASD. Accumulated evidence also shows an important role of epigenetic factors, such as DNA methylation, histone modification, and noncoding RNA, in ASD etiology. In this review, we compiled the research published to date and described the genetic and epigenetic epidemiology together with environmental risk factors underlying the etiology of the different phenotypes of ASD.

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Serap Bilge ◽  
Barış Ekici

Abstract Introduction Autism spectrum disorder is a neurodevelopmental disorder characterized by deficits in communication, social interaction, restricted interest, and repetitive behaviors. Although more cases are being diagnosed, no drugs are approved to treat the core symptoms or cognitive and behavioral problems associated with autism. Therefore, there is an urgent need to develop an effective and safe treatment. Objective In this study, we aim to share our 2-year experience with CBD-enriched cannabis treatment in autism and review the latest studies. Materials and methods The study included 33 (27 males, six females) children diagnosed with autism spectrum disorder who were followed up between January 2018 and August 2020. The mean age was 7.7 ± 5.5 years. The average daily dosage of cannabidiol (CBD) was 0.7 mg/kg/day (0.3–2 mg/kg/day). The median duration of treatment was 6.5 months (3–28 months). The preparations used in this study contained full-spectrum CBD and trace elements tetrahydrocannabinol (THC) of less than 3%. Results The outcomes were evaluated before and after treatment based on clinical interviews. At each follow-up visit, parents were asked to evaluate the effectiveness of the CBD-enriched cannabis treatment. According to the parents’ reports, no change in daily life activity was reported in 6 (19.35%) patients. The main improvements of the treatment were as follows: a decrease in behavioral problems was reported in 10 patients (32.2%), an increase in expressive language was reported in 7 patients (22.5%), improved cognition was reported in 4 patients (12,9%), an increase in social interaction was reported in 3 patients (9.6%), and a decrease in stereotypes was reported in 1 patient (3.2%). The parents reported improvement in cognition among patients who adhered to CBD-enriched cannabis treatment for over two years. The antipsychotic drug could be stopped only in one patient who showed mild ASD symptoms. No change could be made in other drug use and doses. Additionally, this study includes an extensive review of the literature regarding CBD treatment in autism spectrum disorder. According to recent studies, the average dose of CBD was 3.8±2.6 mg/kg/day. The ratio of CBD to THC in the used preparations was 20:1. The most significant improvements were seen in the behavioral problems reported in 20–70% of the patients. Conclusion Using lower doses of CBD and trace THC seems to be promising in managing behavioral problems associated with autism. In addition, this treatment could be effective in managing the core symptoms and cognitive functions. No significant side effects were seen at the low doses of CBD-enriched cannabis when compared to other studies.


2020 ◽  
Vol 10 (5) ◽  
pp. 293
Author(s):  
Hankus Magdalena ◽  
Kazek Beata ◽  
Paprocka Justyna ◽  
Kapinos-Gorczyca Agnieszka ◽  
Magdalena Szczepara-Fabian ◽  
...  

Autism spectrum disorder (ASD) is a neurodevelopmental disorder of multifactorial etiology. Preconception risk factors are still poorly understood. A survey on preconception risk factors for ASD was conducted among parents of 121 ASD patients aged 3–12 years and parents of 100 healthy children aged 3–12 years. The exclusion criteria were as follows: the presence of associated problems such as intellectual disability, epilepsy or other genetic and neurological diseases. Thirteen parameters were considered, a few among which were conception problems, conception with assisted reproductive techniques, the use and duration of oral contraception, the number of previous pregnancies and miscarriages, time since the previous pregnancy (in months), the history of mental illness in the family (including ASD), other chronic diseases in the mother or father and maternal and paternal treatment in specialist outpatient clinics. Three factors statistically significantly increased the risk of developing ASD: mental illness in the mother/mother’s family (35.54% vs. 16.0%, p = 0.0002), maternal thyroid disease (16.67% vs. 5.0%, p = 0.009) and maternal oral contraception (46.28% vs. 29.0%, p = 0.01). Children of mothers with thyroid disorders or with mental illness in relatives should be closely monitored for ASD. Further studies are warranted to assess a potential effect of oral contraception on the development of offspring.


2020 ◽  
Vol 10 (12) ◽  
pp. 951
Author(s):  
Alma Y. Galvez-Contreras ◽  
David Zarate-Lopez ◽  
Ana L. Torres-Chavez ◽  
Oscar Gonzalez-Perez

Autism Spectrum Disorder (ASD) is an early neurodevelopmental disorder that involves deficits in interpersonal communication, social interaction, and repetitive behaviors. Although ASD pathophysiology is still uncertain, alterations in the abnormal development of the frontal lobe, limbic areas, and putamen generate an imbalance between inhibition and excitation of neuronal activity. Interestingly, recent findings suggest that a disruption in neuronal connectivity is associated with neural alterations in white matter production and myelination in diverse brain regions of patients with ASD. This review is aimed to summarize the most recent evidence that supports the notion that abnormalities in the oligodendrocyte generation and axonal myelination in specific brain regions are involved in the pathophysiology of ASD. Fundamental molecular mediators of these pathological processes are also examined. Determining the role of alterations in oligodendrogenesis and myelination is a fundamental step to understand the pathophysiology of ASD and identify possible therapeutic targets.


2019 ◽  
Vol 8 (10) ◽  
pp. 1588
Author(s):  
Yunho Jin ◽  
Jeonghyun Choi ◽  
Seunghoon Lee ◽  
Jong Won Kim ◽  
Yonggeun Hong

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that is accompanied by social deficits, repetitive and restricted interests, and altered brain development. The majority of ASD patients suffer not only from ASD itself but also from its neuropsychiatric comorbidities. Alterations in brain structure, synaptic development, and misregulation of neuroinflammation are considered risk factors for ASD and neuropsychiatric comorbidities. Electroencephalography has been developed to quantitatively explore effects of these neuronal changes of the brain in ASD. The pineal neurohormone melatonin is able to contribute to neural development. Also, this hormone has an inflammation-regulatory role and acts as a circadian key regulator to normalize sleep. These functions of melatonin may play crucial roles in the alleviation of ASD and its neuropsychiatric comorbidities. In this context, this article focuses on the presumable role of melatonin and suggests that this hormone could be a therapeutic agent for ASD and its related neuropsychiatric disorders.


Autism ◽  
2017 ◽  
Vol 22 (6) ◽  
pp. 712-727 ◽  
Author(s):  
Lize De Coster ◽  
Jan R Wiersema ◽  
Eliane Deschrijver ◽  
Marcel Brass

Autism spectrum disorder is a neurodevelopmental disorder that is associated with problems in empathy. Recent research suggests that impaired control over self–other overlap based on motor representations in individuals with autism spectrum disorder might underlie these difficulties. In order to investigate the relationship of self–other distinction and empathy for pain in high-functioning autism and matched controls, we manipulated self–other distinction by using a paradigm in which participants are either imitated or not by a hand on a computer screen. A strong pain stimulus is then inflicted on the observed hand. Behavioral and physiological results in this study showed that overall affective responses while watching pain movies were the same in adults with high-functioning autism as in controls. Furthermore, controls showed higher affective responding after being imitated during the whole experiment, replicating previous studies. Adults with high-functioning autism, however, showed increased empathic responses over time after being imitated. Further exploratory analyses suggested that while affective responding was initially lower after being imitated compared to not being imitated, affective responding in the latter part of the experiment was higher after being imitated. These results shed new light on empathic abilities in high-functioning autism and on the role of control over self–other representational sharing.


Author(s):  
John Elder Robison

There is strong evidence to suggest that individuals with autism spectrum disorder (ASD) are at heightened risk for developing co-occurring psychiatric conditions. However, the reasons behind this increased risk remain unclear. This chapter describes multiple conceptual models of the reasons for comorbidity and appraises the strength for each in relation to currently available evidence. The first section considers the evidence to suggest the reported increase in prevalence can be explained by purely artefactual factors (e.g., issues in sample acquisition or symptom measurement) and concludes this is unlikely as a complete explanation. The second section discusses more theoretical models, and how these could manifest in autistic individuals (e.g., increased prevalence or potency of established risk factors, and the role of ASD-specific risk factors). There is evidence to support multiple mechanisms playing a role in explaining the increased prevalence of psychiatric conditions, and these mechanisms are unlikely to be mutually exclusive. As the current literature is limited, priority areas for future research are suggested, including the need for accurate measurement of predictors and outcomes, more sensitive research designs, and the inclusion of underrepresented groups.


2017 ◽  
Vol 10 (2) ◽  
pp. 76 ◽  
Author(s):  
Zakia Sultana ◽  
Sarder Nasir Uddin ◽  
Asif Ahmed

<p>The aim of this study was to find out the environmental as well as genetic factors responsible for increasing the number of autism spectrum disorder (ASD) patients in Bangladesh. A questionnaire was developed based on 12 environmental factors and genetic aspects. Sixty six patients of ASD and 66 non-ASD control were selected randomly. Among the environmental factors, the age of the mother, premature birth, air pollution, age of the father, hypoxia during childbirth and oral contraceptive came out as significant (p&lt;0.05) factors for ASD incidence compared to the control. Association of multiple factors on an individual was found to be crucial to enhance the risk and exposure to five and six factors was statistically significant (p&lt;0.05) for ASD development. Prospective parents should try to keep the number of risk factors as low as possible before 1-2 months of pregnancy, during pregnancy and 1-2 years after the child birth (for child only).</p>


2021 ◽  
Vol 61 (5) ◽  
pp. 247-52
Author(s):  
Clarissa Josephine Aditya ◽  
Jenni Kim Dahliana ◽  
Ariani Dewi Widodo ◽  
Rini Sekartini

Background Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with a global prevalence of 7.6 in 1,000 children. The Modified Checklist for Autism in Toddlers - Revised (M-CHAT-R) is one of many screening tools for ASD. It is fast, easy to use, and has been translated and validated in the Indonesian language. Objective To determine the prevalence of ASD in Indonesia and its risk factors. Methods A cross-sectional study was conducted from March to October 2020. In the first protocol (March to July 2020), 219 children aged 16-30 months from 20 hospital walk-in clinics in five districts of Jakarta were included. Subjects’ parents filled out the M-CHAT-R questionnaire during their visit. A series of questions were asked to provide information about probable risk factors associated with ASD: gender, family history of ASD, preterm birth, low birth weight (LBW), and history of seizures. The second protocol (August to October 2020) was completed by parents via an online form, where 746 children aged 16-30 months were enrolled. Therefore, a total of 965 subjects were eligible for statistical analysis. Results Of 965 subjects, 56.58% were males. Subjects’ mean of age was 22.59 (SD 4.15) months. M-CHAT-R screening showed that 34 (3.52%) subjects were at high risk of developing ASD. Only male gender was significantly associated with ASD. Conclusion We screened for ASD in healthy 16-30-month-old Indonesian children. The rate of high-risk M-CHAT-R score was 3.52%. Male gender was a significant risk factor for high-risk M-CHAT-R results.


Author(s):  
Bhagavathi Sundaram Sivamaruthi ◽  
Natarajan Suganthy ◽  
Periyanaina Kesika ◽  
Chaiyavat Chaiyasut

Autism spectrum disorder (ASD) is a serious neurodevelopmental disorder characterized by the impairment of the cognitive function of a child. Studies suggested that the intestinal microbiota has a critical role in the function and regulation of the central nervous system, neuroimmune system and neuroendocrine system. Any adverse changes in the gut–brain axis may cause serious disease. Food preferences and dietary patterns are considered as key in influencing the factors of ASD development. Several recent reviews narrated the importance of dietary composition on controlling or reducing the ASD symptoms. It has been known that the consumption of probiotics confers several health benefits by positive amendment of gut microbiota. The influence of probiotic intervention in children with ASD has also been reported and it has been considered as an alternative and complementary therapeutic supplement for ASD. The present manuscript discusses the role of microbiota and diet in the development of ASD. It also summarizes the recent updates on the influence of dietary supplements and the beneficial effect of probiotics on ASD symptoms. An in-depth literature survey suggested that the maternal diet and lifestyle are greatly associated with the development of ASD and other neurodevelopmental disorders. Mounting evidences have confirmed the alteration in the gut microbial composition in children suffering from ASD. However, the unique profile of microbiome has not yet been fully characterized due to the heterogeneity of patients. The supplementation of probiotics amended the symptoms associated with ASD but the results are inconclusive. The current study recommends further detailed research considering the role of microbiome, diet and probiotics in the development and control of ASD.


2021 ◽  
Vol 15 ◽  
Author(s):  
Ala Seif ◽  
Carly Shea ◽  
Susanne Schmid ◽  
Ryan A. Stevenson

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects one in 66 children in Canada. The contributions of changes in the cortex and cerebellum to autism have been studied for decades. However, our understanding of brainstem contributions has only started to emerge more recently. Disruptions of sensory processing, startle response, sensory filtering, sensorimotor gating, multisensory integration and sleep are all features of ASD and are processes in which the brainstem is involved. In addition, preliminary research into brainstem contribution emphasizes the importance of the developmental timeline rather than just the mature brainstem. Therefore, the purpose of this systematic review is to compile histological, behavioral, neuroimaging, and electrophysiological evidence from human and animal studies about brainstem contributions and their functional implications in autism. Moreover, due to the developmental nature of autism, the review pays attention to the atypical brainstem development and compares findings based on age. Overall, there is evidence of an important role of brainstem disruptions in ASD, but there is still the need to examine the brainstem across the life span, from infancy to adulthood which could lead the way for early diagnosis and possibly treatment of ASD.


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