The National Institute of Child Health and Human Development (NICHD) is the lead agency at the NIH collaborating with NAAR in this partnership. "I am extremely pleased that NAAR and NICHD have developed a working partnership," said Dr. Duane Alexander, Director of NICHD. "NAAR's support will help in the search to identify developmental trajectories of children with autism. The information from this study might lead to more effective early diagnosis, and, ultimately, effective interventions."

One of the main themes of the collaboration is how to distinguish children that have different developmental trajectories so clinicians can apply the most appropriate standards to an early diagnostic evaluation and, eventually, to developing specific interventions.

The first research effort to emerge from the High Risk Baby Sibling Autism Research Project is a head circumference study that examines whether rapid head growth in the first sixth months of life is an indicator for autism that could be used as a biological marker. This investigation will attempt to replicate and expand on a promising study by Dr. Eric Courchense, of the University of California at San Diego, that was published last year in the Journal of the American Medical Association (JAMA). Dr. Courchesne's study suggested that children with autism have smaller-than normal head size at birth, followed by a sudden and excessive increase in head size during the first year of life.

The challenge of the head circumference hypothesis is that in the general population, approximately 6% of babies develop large heads in their first months of life. By looking at the infant siblings of children already diagnosed with autism (a high risk population) and tracking their development, researchers with the High Risk Baby Sibling Autism Research Project hope to identify a combination of behavioral and biological diagnostic markers, which may include head circumference.