Down syndrome as a genetic model to evaluate the role of oxidative stress and transsulfuration abnormalities in autism spectrum disorder: A 10‐year longitudinal cohort study

2019 ◽  
Vol 79 (9-10) ◽  
pp. 857-867 ◽  
Author(s):  
David A. Geier ◽  
Janet K. Kern ◽  
Mark R. Geier
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Fazal Abdul ◽  
Nikhitha Sreenivas ◽  
John Vijay Sagar Kommu ◽  
Moinak Banerjee ◽  
Michael Berk ◽  
...  

Abstract Circadian rhythms in most living organisms are regulated by light and synchronized to an endogenous biological clock. The circadian clock machinery is also critically involved in regulating and fine-tuning neurodevelopmental processes. Circadian disruption during embryonic development can impair crucial phases of neurodevelopment. This can contribute to neurodevelopmental disorders like autism spectrum disorder (ASD) in the offspring. Increasing evidence from studies showing abnormalities in sleep and melatonin as well as genetic and epigenetic changes in the core elements of the circadian pathway indicate a pivotal role of circadian disruption in ASD. However, the underlying mechanistic basis through which the circadian pathways influence the risk and progression of ASD are yet to be fully discerned. Well-recognized mechanistic pathways in ASD include altered immune-inflammatory, nitro oxidative stress, neurotransmission and synaptic plasticity, and metabolic pathways. Notably, all these pathways are under the control of the circadian clock. It is thus likely that a disrupted circadian clock will affect the functioning of these pathways. Herein, we highlight the possible mechanisms through which aberrations in the circadian clock might affect immune-inflammatory, nitro-oxidative, metabolic pathways, and neurotransmission, thereby driving the neurobiological sequelae leading to ASD.


2021 ◽  
Vol 11 (7) ◽  
pp. 828
Author(s):  
Maja Roch ◽  
Kate Cain ◽  
Christopher Jarrold

Reading for meaning is one of the most important activities in school and everyday life. The simple view of reading (SVR) has been used as a framework for studies of reading comprehension in individuals with Down syndrome (DS). These tend to show difficulties in reading comprehension despite better developed reading accuracy. Reading comprehension difficulties are influenced by poor oral language. These difficulties are common in individuals with DS and autism spectrum disorder (ASD), but they have never been compared directly. Moreover, the components of reading for comprehension have rarely been investigated in these populations: a better understanding of the nature of reading comprehension difficulties may inform both theory and practice. The aim of this study was to determine whether reading comprehension in the two populations is accounted for by the same component skills and to what extent the reading profile of the two atypical groups differs from that of typically developing children (TD). Fifteen individuals with DS (mean age = 22 years 4 months, SD = 5 years 2 months), 21 with ASD (mean age = 13 years 2 months, SD = 1 year 6 months), and 42 TD children (mean age = 8 years 1 month, SD = 7 months) participated and were assessed on measures of receptive vocabulary, text reading and listening comprehension, oral language comprehension, and reading accuracy. The results showed similar levels in word reading accuracy and in receptive vocabulary in all three groups. By contrast, individuals with DS and ASD showed poorer non-word reading and reading accuracy in context than TD children. Both atypical groups showed poorer listening and reading text comprehension compared to TD children. Reading for comprehension, investigated through a homograph reading accuracy task, showed a different pattern for individuals with DS with respect to the other two groups: they were less sensitive to meaning while reading. According to the SVR, the current results confirm that the two atypical groups have similar profiles that overlap with that of poor comprehenders in which poor oral language comprehension constrains reading for comprehension.


2019 ◽  
Vol 40 (6) ◽  
pp. 1421-1454 ◽  
Author(s):  
Tamar Kalandadze ◽  
Valentina Bambini ◽  
Kari-Anne B. Næss

AbstractIndividuals with autism spectrum disorder (ASD) often experience difficulty in comprehending metaphors compared to individuals with typical development (TD). However, there is a large variation in the results across studies, possibly related to the properties of the metaphor tasks. This preregistered systematic review and meta-analysis (a) explored the properties of the metaphor tasks used in ASD research, and (b) investigated the group difference between individuals with ASD and TD on metaphor comprehension, as well as the relationship between the task properties and any between-study variation. A systematic search was undertaken in seven relevant databases. Fourteen studies fulfilled our predetermined inclusion criteria. Across tasks, we detected four types of response format and a great variety of metaphors in terms of familiarity, syntactic structure, and linguistic context. Individuals with TD outperformed individuals with ASD on metaphor comprehension (Hedges’ g = −0.63). Verbal explanation response format was utilized in the study showing the largest effect size in the group comparison. However, due to the sparse experimental manipulations, the role of task properties could not be established. Future studies should consider and report task properties to determine their role in metaphor comprehension, and to inform experimental paradigms as well as educational assessment.


Author(s):  
Kathryn R. Bradbury ◽  
Emily I. Anderberg ◽  
Lark Huang-Storms ◽  
Iulia Vasile ◽  
Rachel K. Greene ◽  
...  

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