"Stranger Things" fan-favorite Dustin (Gaten Matarazzo) proves that diseases are not detrimental to success, as his actor claims that his rare medical condition made him perfect for the role.

Gaten owes his success and popularity partly due to his rare birth disease called cleidocranial dysplasia, which is a genetic bone condition that causes babies to be born without collar bones. This affected the 15-year-old actor's teeth and his speech, as well as his general appearance, which was written into and incorporated into his character for the show.

"I was born with it, it's a genetic bone condition, it affects pretty much every bone in the body, specifically the skull and the jaw, and the clavicle," said Gaten. The showrunners first discovered Gaten's condition back in the audition room where the child actor's stretching drew the attention of the panel. Gaten had to explain his condition, and the rest was history.

That said, the showrunners did have to ask for the actor's permission to include his condition in the character, where the other kids in the show will bully Dustin because of the said bone defect. Luckily, Gaten was fine with this and even believed it to be a realistic scenario where other people can even relate to, making his character more likeable and interesting.

This was not always the case according to Gaten, since more often than not in the past, he was passed up and rejected for a role due to his teeth and his height. For those who have not seen "Stranger Things," Dustin can be seen without front teeth due to his condition, and this makes his speech impairment quite apparent.

"It's one of the reasons why I haven't been getting roles, because of my lisp, and the teeth situation, and my height. That affected pretty much everything. I would go three times a week for auditions all the time and get constant 'no,'" recalled Gaten.

It was not until "Stranger Things" that the child star found something where he fit in since the showrunners wanted each child in the series to be unique. Gaten will be seen once again in his charming mannerisms and quirky attitude once "Stranger Things" comes back to Netflix for a third season sometime in 2018.