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