[1] Div Publ Hlth, Womens & Childrens Hlth Sect, 5601 Six Forks Rd, Raleigh, NC 27699 USA
[2] State Ctr Hlth Stat, Div Publ Hlth, Birth Defects Monitoring Program, Raleigh, NC USA
[3] Univ N Carolina, Dept Pediat, Chapel Hill, NC USA
[4] Univ N Carolina, Dept Genet, Chapel Hill, NC USA
[5] Duke Univ, Div Plast Maxillofacial & Oral Surg, Durham, NC USA
[6] Univ N Carolina, Sch Dent, Chapel Hill, NC USA
[7] Univ Wisconsin, Dept Comparat Biosci, 2015 Linden Dr W, Madison, WI 53706 USA
[8] Univ N Carolina, Off Provost, Chapel Hill, NC USA