The world’s first patient diagnosed with autism has died in mid-June at the age of 89, his relatives announced.

Donald Triplett, known as “Donald T.” in the scientific literature, he was diagnosed by doctors in 1943 with the neurocognitive disorder called “autism” at the age of 10.

First case recorded in medicine, this American played a key role in defining the disability, and for this reason he gave many interviews and was the subject of a documentary and a book.

As a child, Donald Triplett did not respond to his parents’ demands, showed no interest in other children, but displayed abilities to retain very accurate information and facts about various subjects.

His worried parents wrote a 22-page letter to a child psychiatrist detailing their son’s behaviour. A document that has remained a reference in documenting the symptoms of the disorder.

Despite his diagnosis, which at the time was considered to be severely disabling, Donald Triplett managed to continue his studies and work for more than 60 years on the banks of the small Mississippi town of Forrest.

In 2020, one in 36 children diagnosed with autism in the US, according to research by the Centers for Disease Control and Prevention (CDC).