He spent three years at the Washington University School of Medicine in St. Louis, Missouri where his first daughter Anne Walsh Rimoin was born.
Together with Michael Kaback, he organized a California Tay-Sachs screening program that became a national model.
[1] Rimoin and English geneticist Alan E. H. Emery co-edited Principles and Practice of Medical Genetics, first published in 1983 and now considered an essential textbook on the subject.
[4][5] At Cedars-Sinai he was chair of the pediatrics practice, established an adult genetics program, and began a screening program focused on genetic diseases within Los Angeles' large population of Persian Jews.
It stated that he had found that growth hormone could help pituitary dwarfs achieve close to normal height.