[1] Univ Victoria, Dept Biol, Ctr Environm Hlth, Victoria, BC V8W 3N5, Canada
[2] Penn State Univ, Dept Comp Sci & Engn, University Pk, PA 16802 USA
[3] Hosp Sick Children, Dept Genet, Toronto, ON M5G 1X8, Canada
[4] Texas Tech Univ, Hlth Sci Ctr, Dept Cell Biol & Biochem, Lubbock, TX 79430 USA