[1] UNIV CHICAGO, WYLER CHILDRENS HOSP, DEPT PEDIAT, CHICAGO, IL 60637 USA
[2] UNIV CHICAGO, DEPT BIOCHEM & MOLEC BIOL, CHICAGO, IL 60637 USA
[3] UNIV CHICAGO, JOSEPH P KENNEDY JR MENTAL RETARDAT RES CTR, CHICAGO, IL 60637 USA
[4] RUSH PRESBYTERIAN ST LUKES MED CTR, DEPT BIOCHEM, CHICAGO, IL 60612 USA
[5] RUSH PRESBYTERIAN ST LUKES MED CTR, DEPT ORTHOPED SURG, CHICAGO, IL 60612 USA