ABOVE: Warren sitting at his desk in 1999

Geneticist Stephen Warren died at his home in Atlanta after a brief illness on June 6. Warren was best known for his work identifying the mutations responsible for fragile X syndrome, a genetic disorder linked to intellectual disabilities and certain mood disorders. He was 67.

Warren was born an only child in what was then known as East Detroit in 1953. He told PNAS in a 2015 profile that it was his father, a dentist, who sparked his love of science. In 1972, he began his undergraduate studies at Michigan State University, initially studying zoology. According to a profile by Emory University, Warren’s introduction to genetics came when he started a part-time job running diagnostic tests. He ended up taking every graduate-level genetics course the school offered, and during the summers, he returned to Detroit to work with geneticists at Henry Ford Hospital.

According to Nature Genetics, Warren met his future wife Karen, who would later become a physician, in a genetics lab at Michigan State. Karen then attended medical school in Detroit while Warren remained in East Lansing for his PhD. His thesis was focused on a rare condition known as Bloom syndrome, an inherited disorder linked to high susceptibility to cancer.

See “Recent Trials for Fragile X Syndrome Offer Hope

After getting his degree, Warren took on a postdoc at the University of Illinois at Chicago studying what was then called marker X syndrome (now known as fragile X syndrome), which causes breakages in the ends of X chromosomes. Following his postdoc, in 1985, he was offered a position at Emory to run his own lab. His goal at the time was to find the source of the disorder, which was no small task.

He became an associate professor at Emory in 1991, which is the same year he published a landmark paper in Cell, identifying the cause of fragile X as a mutation in the FMR-1 gene that produces highly methylated CGG repeats more than five times longer than normal. This large, brittle area of the chromosome becomes prone to breakage.

Over the following years, Warren’s lab dug deeper into fragile X. He searched for a function of the FMRP protein that is missing in people with the disorder and found that it binds with mRNAs and slows their translation. Without FMRP, too much protein is made and synapses fire uncontrollably.

Also making 1991 a banner year for Warren, he joined the Howard Hughes Medical Institute (HHMI). Because of his team laying the groundwork, treatments for fragile X were developed, imperfect as they may be. The next year, he became a founding fellow of the American College of Medical Genetics.

Warren left HHMI in 2002 in order to become the founding director of Emory's Department of Human Genetics. When he retired in 2020, he was succeeded in the director position by his colleague Peng Jin.

“Steve was always thoughtful, dedicated and unstintingly generous with his time, his enormous intellect and his impeccable judgment,” Jin remembers in a statement.

He was the first member inducted into the National Institute of Child Health & Human Development Hall of Honor in 2003 and was elected into the National Academy of Medicine the following year. In 2011, he was elected into the National Academy of Sciences. Warren’s final honor came in 2015 when he was elected to the American Academy of Arts and Sciences.

Warren is survived by Karen, their son Thomas, and Thomas’s fiancée.