Olga Tennison Autism Research Centre
Research projects - Biological Markers
Studies which focus on the biological markers of autism complement those conducted on behavioural markers. Charting biological markers will not only help in facilitating more objective diagnosis of the ASDs but, importantly, will enhance our understanding of the biological basis of these conditions. This understanding will ultimately pave the way to effective treatments, if not cures.
1. Growth in children with Autism
The most consistent biological marker in Autism is abnormal brain growth in early life, associated with enlarged head circumferences across all age groups. Together with Dr. Danuta Loesch, and a new PhD student from the M.I.N.D. Institute (Cherie Green), we aim to establish whether growth anomaly in autism is specific to the brain, or also involves general body growth. In our preliminary study we found increased growth in stature in children with high functioning Autism in the first three years of life, and our recent pilot data from older children (6+ years) and adults have confirmed this increased stature. We now hope to undertake a study with mixed-longitudinal design to confirm the hypothesis of general growth dysregulation in Autism in boys aged from 4- to 16-years. We will also explore possible endocrine causes of growth dysregulation in autism.
2. Comorbidity of Autism and Fragile X syndrome
Autism may occur without any discernible cause (idiopathic Autism), or may be associated with a known genetic disorder. One such disorder is Fragile X Syndrome, a common form of intellectual disability, caused by large expansions of a trinucleotide repeat in the X-linked FMR1 (fragile X mental retardation 1) gene. Together with Dr Loesch we aim to establish phenotypic links between Fragile X Syndrome and Autism by comparing behavioural and cognitive profiles between individuals with idiopathic Autism and Autism associated with Fragile X Syndrome. Such comparisons cast light on the biological mechanisms involved in the origin of Autism, since the molecular underpinnings of behavioural and cognitive deficits in Fragile X Syndrome are well understood.
We also explore the possibility that the behavioural and/or cognitive dysfunctions associated with Autism are shared by parents of individuals with Autism in each of the two groups. An NIH grant (Genotype-phenotype relationships in Fragile X) with Dr Loesch and researchers at the M.I.N.D institute) is currently funding part of this research program. We are also conducting molecular studies of rare copy number variants in autism together with colleagues at Murdoch Children's Research Institute in Melbourne.