Department of Genetics, Stanford Medical Center, 300 Pasteur Drive, Lane L 301, Mail Code 5120, Stanford, CA 94305-5120, USA.|Department of Genetics, Stanford Medical Center, 300 Pasteur Drive, Lane L 301, Mail Code 5120, Stanford, CA 94305-5120, USA.|Department of Genetics, Stanford Medical Center, 300 Pasteur Drive, Lane L 301, Mail Code 5120, Stanford, CA 94305-5120, USA.