PRINCETON, NJ – The National Alliance for Autism Research (NAAR) recently invested $480,400 to launch a new study led by renowned scientists Eric Lander, Ph.D. and David Skuse, M.D., Ph.D. that aims to identify a genetic component of a common symptom of autism: the inability to recognize fear as a facial expression.
In order to achieve its goal, the study will focus on Turner Syndrome, which shares a common phenotype with autism: people with autism and Turner Syndrome typically have difficulty identifying fear as a facial expression in other people.
Dr. Skuse, of the Behavioral and Brain Science Unit at the Institute of Child Health in London, has located a region on the X chromosome that appears to be related to the facial recognition phenotype. He and Dr. Lander, director of the Whitehead Institute Center for Genome Research at Massachusetts Institute of Technology in Cambridge, MA, will map this region of the chromosome in the hopes of locating a susceptibility gene for Turner Syndrome, which could play a vital role in determining susceptibility for autism, or at least, an often-observed symptom of autism.
"By using Turner Syndrome – a disorder with a well-defined diagnostic criteria and a disorder that is possibly less genetically complex than autism, the research team hopes to establish as simple a model for gene behavior association as possible," said Andy Shih, Ph.D., director of Research & Programs at NAAR. "It is likely that more than one gene causes autism. Information derived from this study will offer a potential window of insight into the genetics of autism."
The discovery of the genes responsible for this phenotype may lead to the identification of susceptibility genes for both Turner Syndrome and autism and could lay the foundations for a neurological explanation of the key aspects of autism itself.
Turner Syndrome is a disorder of the chromosomes affecting females, where one of the two X chromosomes is partially or completely absent. Most commonly, a patient with Turner Syndrome will be born with 45 chromosomes in each cell rather than 46. The missing chromosome is an X chromosome. Turner Syndrome occurs in approximately one out of every 2,500 births and is associated with normal intelligence.
Because Turner Syndrome occurs only in females, researchers hypothesize that the genes related to the phenotype – the inability to recognize fear as a facial expression – is likely to be linked to the X chromosome.
Along with providing funding for the project, NAAR actually played a critical role in the project forming at all. Dr. Skuse and Dr. Lander met at this year's annual retreat of the Autism Genetics Cooperative at Callaway Gardens in Georgia, which is sponsored by NAAR and the Nancy Lurie Marks Family Foundation. Dr. Skuse made a presentation on Turner Syndrome and the shared phenotype, which attracted the attention of Dr. Lander – a member of the cooperative.
"We are excited to fund this dynamic project between Dr. Skuse and Dr. Lander that aims to explore the genetic roots of autism as well as Turner Syndrome," said Prisca Chen Marvin, NAAR president. "From the start, NAAR has been a strong supporter of research that focuses on the genetics of autism and we remain committed to our search for the answers."