[1] Univ Glasgow, Fac Biomed & Life Sci, Div Mol Genet, Glasgow G11 6NU, Lanark, Scotland
[2] Stanford Univ, Sch Med, Dept Biochem, Stanford, CA 94305 USA
[3] Stanford Univ, Sch Med, Dept Genet, Stanford, CA 94305 USA
[4] Brandeis Univ, Rosenstiel Basic Med Sci Res Ctr, Waltham, MA 02454 USA