Diversity and Classification of Genetic Variations in Autism Spectrum Disorder

Abstract

Autism spectrum disorder (ASD) is a neurodevelopmental condition with symptoms that affect the whole personality and all aspects of life. Although there is a high degree of heterogeneity in both its etiology and its characteristic behavioral patterns, the disorder is well-captured along the autistic triad. Currently, ASD status can be confirmed following an assessment of behavioral features, but there is a growing emphasis on conceptualizing autism as a spectrum, which allows for establishing a diagnosis based on the level of support need, free of discrete categories. Since ASD has a high genetic predominance, the number of genetic variations identified in the background of the condition is increasing exponentially as genetic testing methods are rapidly evolving. However, due to the huge amount of data to be analyzed, grouping the different DNA variations is still challenging. Therefore, in the present review, a multidimensional classification scheme was developed to accommodate most of the currently known genetic variants associated with autism. Genetic variations have been grouped according to six criteria (extent, time of onset, information content, frequency, number of genes involved, inheritance pattern), which are themselves not discrete categories, but form a coherent continuum in line with the autism spectrum approach.

Deficits in olfactory system neurogenesis in neurodevelopmental disorders

“…Moreover, ASD is truly a disorder that occurs on a spectrum, with some individuals requiring little to no assistance with daily functioning and others showing significant deficits in various skills and needing day-to-day support. The causes of ASD are thought to be multifactorial, with environmental (Awadh et al, 2023;Yang et al, 2023), gestational (Sato et al, 2022), and genetic factors (Fang et al, 2023;Ghafouri-Fard et al, 2023;Kereszturi, 2023) at play. Interestingly, several studies have begun to provide evidence that olfactory deficits are a common feature of individuals with ASD.…”

Mesenchymal Stem Cells and Purinergic Signaling in Autism Spectrum Disorder: Bridging the Gap between Cell-Based Strategies and Neuro-Immune Modulation

“…About 0.1% of the whole human genome are single nucleotide variations (SNVs) that take part in creating the unique genetic profile of every individual [ 41 ]. SNVs can be divided into rare mutations and single nucleotide polymorphisms (SNPs).…”

“…De novo CNVs are more often observed in idiopathic ASD amidst simplex families than in multiplex families and those without affected members [40]. About 0.1% of the whole human genome are single nucleotide variations (SNVs) that take part in creating the unique genetic profile of every individual [41]. SNVs can be divided into rare mutations and single nucleotide polymorphisms (SNPs).…”

Binding Folate Receptor Alpha Autoantibody Is a Biomarker for Leucovorin Treatment Response in Autism Spectrum Disorder

“…Although the diagnosis of ASD is defined by behavioral features, both brain-based and systematic biological abnormalities are associated with ASD [2]. Brain-based abnormalities include abnormalities in monoamine neurotransmitter production, imbalances in the excitatory to inhibitory balance, and epilepsy [3][4][5]. Systemic abnormalities including immune dysfunction, oxidative stress and metabolic disorders may also be linked with ASD [6][7][8][9][10].…”