After working for a time as a peddler, Abraham earned enough money to open his own general store. He picked up English quickly and even perfected a rural Wisconsin accent, which helped him build relationships with his clients. Celia, a housewife, retained her strong Yiddish accent.
A childhood accident involving a mill on Celia’s family farm had maimed her left hand, leaving all but her thumb and index finger useless. “Around the age of 5,” said Dr. Rosenberg wrote in his memoir, “while holding his left hand in both mine, I told him that I intended to be a doctor for to be able to fix his hand.”
Leon was an exemplary student: He gave his high school valedictory address and graduated summa cum laude from the University of Wisconsin, where he graduated in 1954 and received his medical degree in 1957. He completed an internship at NewYork-Presbyterian Hospital before joining the National Institutes. of Health as a research fellow in 1959.
His first marriage, to Elaine Lewis, ended in divorce. Along with his wife, he is survived by his brother, Irwin, the former Dean of the School of Nutrition Science and Policy at Tufts University; his sons, Robert Rosenberg and David Korish; his daughters, Diana Clark and Alexa Rosenberg; six grandchildren; and a great-grandchild.
It was at Yale that Dr. Rosenberg conducted research on inherited metabolic disorders, despite his colleagues’ skepticism about the very basis of this work. “Don’t be stupid,” I remembered a nephrologist from Yale telling him. “There is no such thing.”
Dr. Rosenberg proved him wrong. He filled the lectures with case studies of children – Steven, of course, followed by Dana, Lorraine, Robby and others – who presented with inexplicable disorders, which he repeatedly showed were caused by their body’s inability to metabolize various acids, which could often be easily treated.