[1] Univ Washington, Dept Environm & Occupat Hlth Sci, Seattle, WA 98105 USA
[2] Univ Washington, Dept Med, Div Med Genet, Seattle, WA 98105 USA
[3] Univ Washington, Dept Genome Sci, Seattle, WA 98105 USA
[4] Univ Parma, Sch Med, Dept Human Anat Pharmacol & Forens Sci, I-43100 Parma, Italy