While she was a physician in training in Chicago, Sairah Ahmed, M.D., was struck by the similarities between her and a young leukemia patient. Both were intelligent, goal-oriented American women of south Asian descent. They were even the same age. They met and got to know each other throughout the patient’s chemotherapy, hospital stays and toxicity checks.

“She was the only child. Beloved by her parents, aunts, uncles and entire...