[1] Ctr Dis Control & Prevent, Natl Ctr Birth Defects & Dev Disabil, Atlanta, GA 30333 USA
[2] Carter Consulting, Atlanta, GA USA
[3] MassGen Hosp Children, Genet Unit, Boston, MA USA
[4] Massachusetts Dept Publ Hlth, Massachusetts Ctr Birth Defects Res & Prevent, Boston, MA USA
[5] Univ Utah, Dept Pediat, Div Med Genet, Hlth Sci Ctr, Salt Lake City, UT USA
[6] Utah Dept Hlth, Utah Birth Defect Network, Salt Lake City, UT 84116 USA
[7] Colorado Dept Publ Hlth & Environm, Denver, CO USA
[8] Texas Dept State Hlth Serv, Birth Defects Epidemiol & Surveillance Branch, Austin, TX USA
[9] Michigan Dept Community Hlth, Lansing, MI USA