While hosting Saturday Night Live (SNL) over the weekend, Elon Musk made a surprising announcement, revealing that he has Asperger’s syndrome.

The 49-year-old business magnate pointed out that he does not have a lot of variation in his tone when he speaks. He said he is “the first person with Asperger’s to host SNL” before joking that he is “at least the first to admit it.”

Asperger’s syndrome is a developmental disorder, which is part of autism spectrum disorder (ASD), according to the National Institute of Neurological Disorders and Stroke (NINDS).

ASD is a neurological syndrome that is characterized by an impairment in language and communication skills, along with repetitive or restrictive patterns.

NINDS says that one of the characteristic symptoms of Asperger’s is a child’s obsessive interest in a single object or topic. Other symptoms can include repetitive routines, peculiarities in speech and language, clumsiness, inappropriate behavior, poor interaction with peers, and problems with nonverbal communication.

“Children with Asperger’s syndrome are often isolated because of poor social skills and have a history of developmental delays,” says NINDS.

Technically, Asperger’s syndrome is an outdated diagnosis.

In 2013, the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) removed Asperger’s syndrome and was considered an ASD.

Dr. Christopher Hanks of The Ohio State University Wexner Medical Center told Health, “At least in the US and anywhere that uses the DSM-5, Asperger’s is no longer an official diagnosis.”

“The DSM describes autism spectrum disorder now as being ‘mild, moderate, or severe,’ although the criteria for distinguishing among these three levels is somewhat vague and has not yet been validated,” Dr. David Mandell of the University of Pennsylvania Perelman School of Medicine told Health.

“Even highly experienced and skilled clinicians were unable to agree on cases,” Dr. Mandell explained. “That is, clinicians were not reliable in differentiating between Asperger’s and autism. Part of the reason for this is that the presentation of autistic people can change dramatically with age and over time.”

Dr. Hanks said Asperger’s was also removed as an official diagnosis to “clarify that autism is a broad spectrum and that it can manifest in different ways in individuals.”

Dr. Mandell said, “There was a lot of controversy among scientists, clinicians, and advocates when Asperger’s was removed from the DSM.” The article was published on Health.