Scientists that focus on understanding the risk factors and the earliest signs of autism met on January 28-29 to share new findings and ideas at the annual meeting of Autism Speaks' sponsored High Risk Baby Siblings Research Consortium (BSRC). The day-long symposium focused on two topics of interest: regression and the broader autism phenotype. Each investigator provided new information and perspective emerging from their studies that track the development of high risk infant siblings throughout early life. Siblings of children diagnosed with autism spectrum disorder (ASD) are at higher risk than the general population for developing ASD or related symptoms, and therefore longitudinal studies examining their development are helping to shed light on the early course of ASD.
The group discussed the challenges of defining regression, which can vary from an abrupt and dramatic loss of skills in several domains to a more gradual loss of only a subset of skills. Data obtained by prospectively studying infants at-risk for developing autism offers a detailed look at early signs and different patterns of onset. For example, longitudinal studies are documenting that the patterns of onset of autism are quite variable, ranging from early onset of symptoms during the first year of life, to a plateauing of development during the second year, to actual loss of skills that were previously obtained. These variable patterns of onset underscore the challenges of developing reliable methods for early detection that are able to capture all children at-risk for ASD. Despite the challenges, the investigators agreed that by defining and studying regression, it may be possible to discover whether different patterns of ASD are associated with different causes, prognoses, or treatment responses. "For decades, our understanding of regression relied only on parental retrospective reports or home videotapes," noted Geri Dawson, Chief Science Officer at Autism Speaks, who attended the conference. "These prospective studies of high risk infants are shedding new light on the patterns of onset of ASD."
The other topic of interest was the aforementioned broader autism phenotype. The broader autism phenotype refers to symptoms that are qualitatively similar to autism but are not severe enough to be considered a clinical diagnosis. Understanding these sub-clinical but noticeable signs in families is helpful in examining the genetics of autism and familial risk factors. About 10-15% of siblings of children with autism show mild symptoms related to autism but do not meet diagnostic criteria for ASD. This phenomenon was addressed by BSRC member John Constantino at the IMFAR meeting last year. Investigators at this meeting now reported that siblings showing the broader phenotype may have difficulties in the areas of social interaction and language, as well as biological differences measured through neurophysiological findings including increased head circumference, eye tracking differences, and changes in brain waves (measured as electroencephalographic, or EEG, activity). It is important that these differences can be understood and recognized so that a child needing help can get treatment as soon as possible.
Additionally, many of the BSRC scientists studying early signs and symptoms of autism are part of the Autism Speaks' supported Toddler Treatment Network (TTN). Now that the BSRC-led research is allowing diagnoses to be made much earlier, the TTN investigators are developing and testing novel approaches to early intervention appropriate for infants as young as 12 months of age. In 2006, Autism Speaks provided funding to several investigators to test different methods of intervention for toddlers with ASD. Following the BSRC meeting, these investigators met for a day to update each other on their progress and challenges. Findings are preliminary but promising. All studies are testing interventions that can be implemented by parents in a variety of settings. "Development changes over time, and missing a particular marker or having one or more of the 'red flags' does not necessarily mean that a child has, or will ultimately have autism," says Sally Rogers, Ph.D., the principal investigator on one study using the Denver Early Start Model for intervention. As further explanation of the advantage of parent-mediated interventions, she states, "However, it is beneficial to any child — whether or not he or she has autism — to receive help in catching up with any missed or delayed developmental milestones." She continues, “There are reports that this type of intensive treatment early in life significantly improves the development of useful speech and decreases the severity of cognitive impairments in children with autism. However, most interventions are designed for older preschoolers. It's time to find out if they work or need to be adjusted for the very young. This is especially important as we are able to diagnose autism earlier and earlier. It is essential to have treatment options with proven results to recommend to children of any age once the diagnosis of autism is given."
Although the TTN projects use different intervention models, there are commonalities across studies. Therefore, investigators in the TTN decided on a set of common diagnostic and outcome measures so that comparisons across the studies can be made. The interventions involve techniques that can be implemented outside the clinic, allowing parents and caregivers to use these techniques in different settings, decreasing the time between parent's initial concern and beginning intervention, thus hopefully improving developmental outcome in the long run. Because they require less "in clinic" time, they may also be very cost effective.
A summary of each of these projects can be found on our Toddler Treatment Network page here.