[1] Univ Wisconsin, Dept Med Genet, Madison, WI 53706 USA
[2] Shodair Childrens Hosp, Helena, MT 59604 USA
[3] Univ Chicago, Genet Serv, Chicago, IL 60637 USA
[4] Perinatal Associates, Obstetrix Med Grp, Renton, WA 98055 USA
[5] Kaiser Permanente, Dept Genet, Clackamas, OR 97015 USA