Following military service in World War II, he returned to Johns Hopkins for a residency in pediatrics.
[2] He remained a professor emeritus in the Department of Pediatrics at the Johns Hopkins University School of Medicine until his death.
Childs studied the genetics of adrenal hyperplasia, Crigler–Najjar syndrome, and propionic acidemia.
He is known for his collaboration with William H. Zinkham, which demonstrated that Glucose-6-phosphate dehydrogenase deficiency is an X-linked recessive genetic disease.
He is best known for a collaboration with Ronald Davidson and Harold Nitowsky, which demonstrated random inactivation of one of the two X-chromosomes in mammalian female cells, a mechanism of dosage compensation.