International Meeting for Autism Research (May 7 - 9, 2009): Under-Representation of African Americans in Autism Genetic Research: a Rationale for Inclusion of Subjects Representing Diverse Family Structures

Under-Representation of African Americans in Autism Genetic Research: a Rationale for Inclusion of Subjects Representing Diverse Family Structures

Thursday, May 7, 2009: 1:30 PM
Northwest Hall Room 1 (Chicago Hilton)
C. Hilton , Psychiatry (Child), Washington University School of Medicine, St. Louis, MO
K. M. Jackson , Department of Psychiatry, Washington University School of Medicine, St. Louis, MO
R. Fitzgerald , Department of Psychiatry, Washington University School of Medicine, St. Louis, MO
R. Maxim , Knights of Columbus Developmental Center, Saint Louis University, St. Louis, MO
C. Bosworth , Special School District of St. Louis County, Town and Country, MO
J. N. Constantino , Psychiatry (Child), Washington University School of Medicine, Saint Louis, MO
Background: Differences in the contributors of genetic susceptibility to disease have been observed as a function of ethnic/ancestral origin for a number of medical and psychiatric conditions.  African American children with autism are currently grossly under-represented in existing genetic registries and genetic studies of autism. 
Objectives: In this retrospective analysis we explored barriers to participation of African American families in autism genetic research.
Methods:
We estimated the number of autistic children of African American descent in our geographic region using CDC surveillance data from our Autism and Developmental Disorder Monitoring (ADDM) site.  In this context, we reviewed the outcomes of our ongoing efforts to recruit and enroll African American families into either of two large national genetic registries: the Autism Genetic Resource Exchange (AGRE) and the Simons Simplex Collection (SSC). Over the period of this data collection, the requirements for both registries included availability of both parents and at least one full biological sibling. 
Results:
 Extrapolating from the CDC 2002 St. Louis Autism and Developmental Disabilities Monitoring findings, we estimated that 730 African American children in metropolitan St. Louis, Missouri between ages 3 and 21 have an autism spectrum disorder.  Of those, only 49% have received a clinical diagnosis by a medical service specializing in neurology, psychiatry, or developmental disorders (the usual sources of recruitment for autism genetic studies). We selected a clinical source serving the highest number of African American children with autism per year in our region, and identified 73 diagnosed children who were considered for enrollment in either SSC or AGRE.   Of the 73 identified families, 28 had no siblings or no full siblings available to participate in the study, 17 could not be located from the contact information provided by the clinical service, 11 represented single-parent households with the other parent unable or unavailable to participate; 3 of the probands were adopted; 3 were born prematurely (and therefore excluded on the basis of registry criteria), 3 had comorbid developmental conditions excluded by the retrospective registries.  The remaining 12 (16%) qualified and enrolled.
Conclusions:
Based upon these findings we estimate that without modifications to typical exclusion criteria, only 8% of all children of African American descent with ASD in our region would be identifiable through medical sources and eligible for inclusion in existing autism genetic registries.  Comprehensive efforts--including the acceptance of participation of families of diverse structure--to facilitate the inclusion of African American children in existing registries is warranted.  Any resulting compromise of the ability to establish identity by descent in genetic analyses may well be outweighed by availability of a critical number of African American probands to test and replicate genetic findings using case-control methods.
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