A 33-year-old woman is going viral on TikTok after she started posting videos showing her extremely rare genetic disorder that causes her muscles in the jaw to attach to her left eyelid.

Mandy Bardisbanian is one of only 300 people in the world who suffers from a rare condition called Marcus Gun syndrome. The disorder causes her eyelids to move up and down whenever she moves her jaw.

The disease is named after a UK doctor Marcus Gunn who discovered the rare condition when a 15-year-old from England presented herself with the condition.

The disease is registered with the National Organization for Rare Diseases (NORD). The defining characteristic of this disorder is the involuntary movement of the affected eyelid in tandem with any movement of the lower jaw. This causes the eye appears to open more.

The disease is easily identified at birth. As suckling involves jaw movements, it causes the eyelids of the babies born with this syndrome to move up and down, as per Dagbladet.

Bardisbanian, of Long Beach, California, admitted that the rare condition badly affected her self-esteem growing up and also made her a target for bullies.

‘I was a very bullied child when you picture the meanest, dorkiest kid, I was. It was incredibly difficult for me because the kids were mean. I self-harmed as a child, it was incredibly difficult to grow up with such a thing,” Bardisbanian said, NewstimeUK reported. ‘Even though it’s not the worst thing you’ve ever had, it sucked, it’s okay to suck it.’

The exact reason why the condition happens remains unclear.

The Californian woman has launched a campaign to find other people suffering from the same condition and now heads a 2,000-member Facebook support group for her condition. ‘It’s also a way to reclaim my power, now I want to start an anti-revolutionary charity,’ she said of the Facebook group.

‘Some people reach out to me and say they have it and they hate it, but my videos give them hope. I even had a girl from high school who reached out to me and apologized for how mean she was to me at school,” Bardisbanian continued.

‘The hardest part is always hitting the post because I’m revealing something about myself that I’ve tried to hide my whole life,’ Bardisbanian said.