The Autism Birth Cohort Study - Status and Future Plans

Background: The Autism Birth Cohort (ABC) Study is a scientific collaboration between the Norwegian Institute of Public Health, the Mailman School of Public Health at Columbia University and the National Institutes of Health / National Institutes of Neurological Disorders and Stroke (NIH/NINDS). It is supported by a five-year grant from NIH/NINDS. The ABC Study is a sub-study of the Norwegian Mother and Child Cohort Study (MoBa), which is a Norwegian population-based pregnancy cohort including about 110,000 children.  

Objectives: The scientific aims of the ABC Study are to: (1) establish the Autism Birth Cohort through ascertainment of autism spectrum disorder (ASD) cases from the MoBa cohort, (2) identify environmental factors that may be directly or indirectly associated with ASD, and (3) describe the natural history of clinical, anthropometric and neurobehavioral features of ASD.

Methods: Subjects are recruited into MoBa at week 17-18 of pregnancy. Parents complete questionnaires throughout pregnancy and at intervals following birth (6, 18, 36 months, 7 and 8 years). The data are linked to the Medical Birth Registry of Norway (MBRN). Blood samples are collected from the mother (prenatal and at birth), the father (prenatal) and the child (cord blood at birth). Plasma, DNA and RNA are stored in the MoBa Biobank at -80 degrees C. 
Potential ASD cases are identified via three mechanisms: (1) ASD screening of the MoBa cohort in the 36-month questionnaire, (2) referrals by parents or from the healthcare system, and (3) linkage with the Norwegian Patient Registry. The ASD screening is based on the Social Communication Questionnaire (SCQ). There is also a control group of subjects randomly selected from the cohort. Potential cases and controls are invited to a clinical assessment designed to collect detailed neurobehavioral and developmental information and to generate a diagnosis of ASD or associated disorders. The core diagnostic instruments are the ADOS and the ADI-R.

Results: By December 2008, a total of 33,000 MoBa participants have been screened for ASD. Around 500 children have been clinically assessed. All MoBa participants will attain 36 months by mid-2012. Pilot studies of randomly selected Biobank specimens indicate their viability for transcript profiling, proteomics, serology and genetic analyses.

Conclusions: The scientific analyses of the collected data and biological materials have started, with two main focus areas in the initial phase: (1) investigations of potential biomarkers of ASD in child cord blood and (2) child population screening for ASD. Preliminary results will be presented at the conference.