Evaluation of Prenatal and Perinatal Risk Factors for Tourette Syndrome and Chronic Tic Disorders in a Large, Prospective, Population-based Cohort

Grant Type
Grant Year
Institution Location
Institution Organization Name
Massachusetts General Hospital
Investigators Name
Scharf, Jeremiah, MD, PhD

Despite the fact that Tourette Syndrome (TS) and chronic tic (CT) disorders are highly heritable, twin and family studies have consistently demonstrated that additional, non-genetic factors play a significant role in the development of these conditions. Previous studies have reported a number of candidate “environmental” TS or CT risk factors, particularly events or exposures arising in the prenatal or perinatal period (during pregnancy and delivery). Unfortunately, these studies have produced conflicting results, possibly because of hidden biases related to their retrospective designs, the limited availability of well-documented environmental exposures or the lack of a comparable unaffected control group. Thus, there is a great need to examine these potential non-genetic/environmental TS/CT risk factors in a set of individuals where detailed information about the candidate risk factors are identified prior to the onset of any tic symptoms. In this project, we plan to evaluate the previously reported candidate prenatal and perinatal TS/CT risk factors in a large, prospective, longitudinal British pre-birth cohort, the Avon Longitudinal Study of Parents and Children (ALSPAC). This unique epidemiologic sample contains data collected from all children born to mothers in a specific geographical area over 21 months between 1991-1992, including questionnaires completed during pregnancy, birth records and serial questionnaires about parental health, child development, environmental exposures and health outcomes every 6-12 months from birth to the present. We will test whether existing non-genetic TS/CT risk factors are present more frequently in children who develop motor and/or vocal tics by age 13 compared to unaffected subjects from the cohort sample. We will also explore whether any of these factors are risk factors for co-morbid obsessive compulsive disorder (OCD) or attention- deficit hyperactivity disorder (ADHD). We anticipate that this research will contribute toward improved understanding of the underlying causes of TS and CT and will lay the foundation for future gene-by-environment interaction studies that could identify the specific mechanisms through which these nongenetic factors contribute to the development of these conditions. Jeremiah M. Scharf, M.D., Ph.D. Massachusetts General Hospital, Boston, MA Yoav Ben-Shlomo, M.D., Ph.D. University of Bristol Bristol, United Kingdom Carol Mathews, M.D., University of California San Francisco, CA Award: $75,000 Commentary: Although TS is an inherited condition scientists believe that other non-hereditary factors might influence the development of the disorder. In this study, Drs. Scharf, Ben-Shlomo and Mathews using a large database from the United Kingdom (UK) that contains information on the lifestyle, environment and health of parents and their children, will examine whether environmental influences during pregnancy and/or birth could increase a child’s risk of developing TS and associated conditions such as OCD and ADHD. Tourette Association of America Inc. – Research Grant Award 2009-2010