Integrated Functional Analysis Implicates Syndromic and Rare Copy Number Variation Genes as Prominent Molecular Players in Pathogenesis of Autism Spectrum Disorders

Copy number variations in autistic children

Autism spectrum disorder (ASD) manifests as a neurodevelopmental condition marked by challenges in social communication, interaction and the performing of repetitive behaviors. The prevalence of autism increases markedly on an annual basis; however, the etiology remains incompletely understood. Cytogenetically visible chromosomal abnormalities, including copy number variations (CNVs), have been shown to contribute to the pathogenesis of ASD. More than 1% of ASD conditions can be explained based on a known genetic locus, whereas CNVs account for 5-10% of cases. However, there are no studies on the Saudi Arabian population for the detection of CNVs linked to ASD, to the best of our knowledge. Therefore, the aim of the present study was to explore the prevalence of CNVs in autistic Saudi Arabian children. Genomic DNA was extracted from the peripheral blood of 14 autistic children along with four healthy control children and then array-based comparative genomic hybridization (aCGH) was used to detect CNVs. Bioinformatics analysis of the aCGH results showed the presence of recurrent and non-recurrent deletion/duplication CNVs in several regions of the genome of autistic children. The most frequent CNVs were 1q21.2, 3p26.3, 4q13.2, 6p25.3, 6q24.2, 7p21.1, 7q34, 7q11.1, 8p23.2, 13q32.3, 14q11.1-q11.2 and 15q11.1-q11.2. In the present study, CNVs in autistic Saudi Arabian children were identified to improve the understanding of the etiology of autism and facilitate its diagnosis. Additionally, the present study identified certain possible pathogenic genes in the CNV region associated with several developmental and neurogenetic diseases.

SYNGAP1-related developmental and epileptic encephalopathy: The impact on daily life

SYNGAP1-developmental and epileptic encephalopathy (SYNGAP1-DEE) has been recently featured as a distinct genetic disease characterized by global psychomotor delay mainly involving language, moderate-to-severe cognitive impairment, autism spectrum disorder, and a generalized epilepsy with spontaneous and reflex seizures. The severity and variability of function impairment and the impact on patients' and caregivers' daily life are still poorly acknowledged. The SYNGAP1 Italian Family Association developed a survey, shared online with caregivers, exploring several issues, including: epilepsy outcome, comorbidities, daily-living skills, hospitalizations, rehabilitation treatments, economic burden, and COVID-19 pandemic impact. Caregivers of 13 children and adolescents participated in the survey. They most often show a fine and gross-motor impairment and a drug-resistant epilepsy with possibility to experience pluridaily absence seizures that may lead to periods of psychomotor regressions. Eating and sleep problems are reported in the majority. Most parents are concerned about language impairment, behavioral issues and lack of autonomy in daily-living activities. Specific neuropsychological evaluations for autism should be early considered in order to identify intervention strategies involving alternative communication strategies, which can positively affect behavior and quality of life. Rehabilitation treatment should aim to the acquisition and consolidation of personal autonomy.

Molecular Dysregulation in Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) comprises a heterogeneous group of neurodevelopmental disorders with a strong heritable genetic component. At present, ASD is diagnosed solely by behavioral criteria. Advances in genomic analysis have contributed to numerous candidate genes for the risk of ASD, where rare mutations and s common variants contribute to its susceptibility. Moreover, studies show rare de novo variants, copy number variation and single nucleotide polymorphisms (SNPs) also impact neurodevelopment signaling. Exploration of rare and common variants involved in common dysregulated pathways can provide new diagnostic and therapeutic strategies for ASD. Contributions of current innovative molecular strategies to understand etiology of ASD will be explored which are focused on whole exome sequencing (WES), whole genome sequencing (WGS), microRNA, long non-coding RNAs and CRISPR/Cas9 models. Some promising areas of pharmacogenomic and endophenotype directed therapies as novel personalized treatment and prevention will be discussed.

Health-Related Quality of Life in Pediatric Patients with Syndromic Autism and their Caregivers

Children with autism have a significantly lower quality of life compared with their neurotypical peers. While multiple studies have quantified the impact of autism on health-related quality of life (HRQoL) through standardized surveys such as the PedsQL, none have specifically investigated the impact of syndromic autism. Here we evaluate HRQoL in children diagnosed with three genetic disorders that strongly predispose to syndromic autism: Phelan-McDermid syndrome (PMD), Rett syndrome (RTT), and SYNGAP1-related intellectual disability (SYNGAP1-ID). We find the most severely impacted dimension is physical functioning. Strikingly, syndromic autism results in worse quality of life than other chronic disorders including idiopathic autism. This study demonstrates the utility of caregiver surveys in prioritizing phenotypes, which may be targeted as clinical endpoints for genetically defined ASDs.