Saul W. Brusilow, an internationally renowned pediatrician and biochemical geneticist, died on April 19. He was 92.

During his 52-year career at Johns Hopkins, Brusilow discovered biochemical therapies that successfully combated a group of genetic abnormalities collectively known as urea cycle disorders. Without the treatments he manufactured and patented, children and older patients otherwise would have died or suffered brain damage due to the accumulation of toxic digestive byproducts in their systems.

George Dover, director of the Department of Pediatrics and the Johns Hopkins Children’s Center from 1996 to 2016, says Brusilow “was a champion for young faculty and fellows who wished to become clinician/scientists, and many of us quickly were attracted to him for his advice and mentorship.”

Brusilow served from 1959 to 1968 as director of Johns Hopkins’ Cystic Fibrosis Clinic, where he developed the sweat chloride test, now considered the gold standard for diagnosing whether children have the disease. He also led the Division of Pediatric Nephrology from 1969 to 1981 and the Division of Metabolic Diseases from 1981 to 1998.

Geneticist David Valle, professor and director of Johns Hopkins’ Institute of Genetic Medicine, worked closely with Brusilow for years. “He’s best described by a string of adjectives — he was irreverent, rigorous, creative, irascible and mercurial,” Valle wrote in an email.

“He was the greatest clinical investigator I have ever met. He took wonderful care of his patients but was rough on almost everyone else. … He developed all of the medicines that today are the state-of-the-art medicines for treating urea cycle disorders.”