Autism Spectrum Disorders: Identification of Novel Microdeletion and Microduplication Syndromes and Clinical Endophenotypes

Autism spectrum disorders (ASDs) affect more than one in 250 people and are characterized by significant impairments in social interactions and communication as well as inappropriately focused behaviours and restricted interests. Research involving sibling, twin and family studies has revealed the predominant role of genetic factors in ASDs and also identified regions in chromosomes where genes conveying susceptibility to ASDs might be located. Furthermore, recent studies have shown that chromosome anomalies can be found in five to 28 per cent of persons with ASDs, depending on whether they have cognitive delay and/or physical anomalies. Noemie Riendeau is exploring the genomic changes and molecular genetics underlying ASDs, as well as their clinical presentation and associated genomic syndromes. She is using a genome screening method known as Comparative Genomic Hybridization (array-CGH) to detect small chromosomal imbalances called microdeletions and microduplications in people with autism. The hope is that identifying these imbalances will help pinpoint genomic regions where genes associated with Autism Spectrum Disorders (ASDs) are located. The research also investigates how these genomic changes correlate with the clinical phenotypes of the patients, especially those with dysmorphic features and/or intellectual disability, but also for those cases described as simple autism. By defining new microdeletion and microduplication syndromes, this research will contribute to a better understanding of the genetic basis of ASDs and potentially to improved methods for early detection and treatment.