[1] Univ Michigan Hlth Syst, Dept Internal Med, Div Endocrinol & Metab, Ann Arbor, MI USA
[2] Univ Chicago, Howard Hughes Med Inst, Chicago, IL 60637 USA
[3] Univ Chicago, Dept Biochem & Mol Biol, Chicago, IL 60637 USA
[4] Univ Chicago, Dept Med, Chicago, IL 60637 USA
[5] Univ Chicago, Dept Human Genet, Chicago, IL 60637 USA
[6] Washington Univ, Sch Med, Dept Med, St Louis, MO 63110 USA
[7] Washington Univ, Sch Med, Dept Cell Biol & Physiol, St Louis, MO 63110 USA