Recorded presentation

Martha Herbert, MD, PhD, Pediatric Neurology and Center for Morphometric Analysis, Harvard Medical School, 149 - 13th Street, Room 6012, Charleston, MA 02129, 617-724-5920, mherbert1@partners.org

The study of biomarkers in learning and developmental disabilities is marked by much variability and inconsistency in findings. While this may frustrate models presuming that etiologies are primarily genetic, it is expectable in the setting of gene-environment interaction models. Brain development can be altered by many factors, including chemicals, hormones and cytokines, whose impacts may include altered cell size, cell number, packing density, and arborization. The distribution and severity of such changes may vary in relation to complexities of timing, and of mechanisms of exposure and histogenetic injury. This may at least in part account for the marked variability in anatomical, neurochemical and functional profiles of individuals who nevertheless meet the broad defining behavioral criteria of specific neurobehavioral disorders. In addition, many different disease states may lead to specific neurobehavioral syndromes such as autism, further suggesting heterogeneity of mechanism and vulnerability. The biological heterogeneity of these disorders impedes achievement of statistical significance in investigations of biological and environmental risk factors. Models of systems disruption may be more suitable for modeling both causation and functional impairment than attempts to find single genes, toxins, neurotransmitters or neural systems dysfunctions. A systems disruption model may provide a means for the systematic incorporation of multiple endophenotypes into research programs. Levels at which systems disruption models may be formulated will be reviewed.

Learning Objectives:

• Participants will learn about gene-environment interactions in learning anddevelopmental disabilities
• Participants will have a greater understanding of biological heterogeneity inlearning and developmental disabilities ) Participants will gain insight into the utility of incorporating systemsmodels of learning and developmental disabilities into research on environmentalrisk factors.

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.

Recorded presentation