Colleen O'Ryan | Genetic Autism Cape Town
|Research | Publications | Collaborations | Lab members | Resources|
Dr Colleen O'Ryan
firstname.lastname@example.org | Telephone +27 21 650 4257 | Facsimile +27 21 650 1861
|I am an established population and evolutionary genetics researcher as can be seen from my earlier publications. However, my research group has been investigating genotype-phenotype associations of Autism Spectrum Disorders (ASD) since 2014. Much of the published autism literature reports on ASD genetic data from northern hemisphere populations with few genetic studies examining South African children with ASD. Autism Spectrum Disorder is an early onset developmental disorder with an incidence of one in 132 people. It is defined in the DSM-V (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition) as being characterised by deficits in two core symptom domains: social communication and fixated interests and repetitive behaviour or activities.
ASD is a quantitative trait resulting from multiple interacting genes as well as epigenetic and environmental influences. ASD symptom severity ranges from individuals who have no spoken language and who have intellectual disabilities and co-morbidities like epilepsy, to individuals who have fluent language, average cognition and mild social and behavioural difficulties. Although there is a large body of literature linking ASD to candidate genes, the literature appears contradictory because ASD represents numerous 'subtypes' or 'endophenotypes' which are often not clearly defined.
ASD is a highly heritable disorder and recent reports of the discordance of ASD symptoms observed in monozygotic twins implicate epigenetic mechanisms, like DNA methylation, in its aetiology. Epigenetic mechanisms allow for articulation between genetics and the environment by responding to environmental cues, thus modulating gene expression. A major focus of this group is the epigenetics of ASD, and a recent whole genome DNA screen identified several differentially methylated genes associated with ASD in our South African cohort.
The objectives of our group include building a clearly phenotyped cohort of South African children, examining the epigenome in our study cohort, and validating the expression levels of these differentially methylated genes.
S. Stathopoulos, R. Gaujoux and C. O’Ryan. 2018 Mitochondrial dysfunction and DNA damage in children with Autism Spectrum Disorder. (under review)
*E. H. Harley, M. de Waal, S Murray, and C. O’Ryan. 2016. Comparison of whole mitochondrial genome sequences of northern and southern white rhinoceroses (Ceratotherium simum): The conservation consequences of species definitions. Conservation Genetics. DOI 10.1007/s10592-016-0861-2.
*N.M.S. Techow, C. O’Ryan, C.J.R Roberson and P.G. Ryan. 2016. The origins of white-chinned petrels killed bylong-line fisheries off South Africa and New Zealand. Polar Research 35, 21150.
*N. Muna and C. O’Ryan. 2016. Isolation and characterisation of the first microsatellite markers for the southern harvester termite, Microhodotermes viator. Bulletin of Entomological Research 1:1-6.
*S. Stathopoulos, J.M. Bishop, C. O’Ryan. 2014. Genetic signatures for enhanced olfaction in the African mole-rats. Plos One 9(4): e93336.
T. Theka, A. Rodgers, D. Webber, C. O'Ryan. 2014. Variability in Kidney Stone Incidence Between Black and White South Africans: AGT Pro11Leu Polymorphism Is Not a Factor. Journal of Endourology, 25(5):577 -581. (DOI: 10.1089/end.2013.0617).
Dr Renauld Gaujoux (Department of Immunology, Technion – Israel Institute of Technology)
Sofia Statphopoulos - Postdoctoral Researcher
|Autism Western Cape: www.autismwesterncape.org.za
Autism Speaks: www.autsimspeaks.org