Dr. Guthrie was born in Marionville, MO, in 1916. He grew up in Minnesota, where he earned his medical degree in 1942 and his PhD in bacteriology in 1946 at the University of Minnesota. For the first 12 years of Dr. Guthrie’s career, he was a principal cancer scientist at the Roswell Park Cancer Institute in Buffalo, NY. During this time, Dr. Guthrie’s second son John was born mentally handicapped (1947) and his 15-month-old niece was diagnosed with PKU (1958). By Dr. Guthrie’s own account, it was the birth of his second son John that motivated him to pursue research aimed at preventing mental retardation and developmental disabilities. It was the birth of his niece that brought to his attention the treatable causes of mental retardation.

https://academic.oup.com/labmed/article/40/12/748/2588794