Korf received his M.D. from Cornell University Medical College and his Ph.D. in genetics and cell biology from Rockefeller University. He completed a residency in pediatrics, pediatric neurology, and genetics at Children's Hospital, Boston. Prior to his appointment at the University of Alabama, he served as clinical director in the Division of Genetics at Children's Hospital from 1986 to 1999, and as the medical director of the Harvard-Partners Center for Genetics and Genomics from 1999 to 2002. He was associate professor of neurology at Harvard Medical School and directed postdoctoral training in medical and laboratory genetics at hospitals affiliated with Harvard. Korf's principal area of research is neurofibromatosis.
Korf is the author of Human Genetics: A Problem-Based Approach, an introductory graduate textbook used by medical students and genetic counselors. He is co-author, with Dorian Pritchard, of Medical Genetics at a Glance, and an editor of Emery and Rimoin's Principles and Practice of Medical Genetics.