Department of Genetics, Dartmouth Medical School, Lebanon, NH 03756, USA.|Department of Genetics, Dartmouth Medical School, Lebanon, NH 03756, USA.|Department of Genetics, Dartmouth Medical School, Lebanon, NH 03756, USA.|Department of Genetics, Dartmouth Medical School, Lebanon, NH 03756, USA.|Department of Genetics, Dartmouth Medical School, Lebanon, NH 03756, USA.|Department of Genetics, Dartmouth Medical School, Lebanon, NH 03756, USA.