 The son of John Clement York, a dentist who died when York was 15, York grew up in Little Rock and attended local schools until college.He graduated from the University of Notre Dame in South Bend, Indiana in 1971.He received a doctorate in blood pathology from Stritch School of Medicine at Loyola University Chicago in 1975, and engaged in seven years of post-doctoral study, specializing in the laboratory diagnosis of lymphoma and leukemia.