Biomarkers in the Study of Families of Individuals with Developmental Disabilities.

Research during the past 20 years on families of children with developmental disabilities has yielded a rich body of knowledge about the stress of parenting a child with DD, and the risk and protective factors that result in profiles of family resilience vs. vulnerability at various stages of the family life course. Virtually all of this research has been based on data collected from self-report measures, and has focused on family interactions and relationships, and the psychosocial well-being of individual family members. The present chapter focuses on different sources of data, namely biomarkers, which have the potential to extend our understanding of the biological mechanisms by which the stress of parenting a child with developmental disabilities can take its toll on parents' physical and mental health. We focus on two examples: (1) variations in the FMR1 gene, FMRP, and FMR1 messenger RNA in mothers of children with fragile X syndrome and the association of these measures with maternal depression and anxiety; and (2) profiles of cortisol expression in mothers of children with disabilities and the association of cortisol with daily measures of caregiving stress.