Jay Seegmiller and his colleagues at NIH discovered that the rare genetic disease, Lesch–Nyhan syndrome, was due to a profound deficiency of an enzyme known as hypoxanthine guanine phosphoribosyltransferase, or HGPRT. They reported this as "the first example of a relation between a specific enzyme defect and abnormal compulsive behavior and simultaneously as the 1st enzyme defect in purine metabolism demonstrated in a neurological disease."

Order of authorship in the original publication: Seegmiller, Rosenbloom, Kelly.

(Thanks to Juan Weiss for this reference and its interpretation.)