Though this marks the first sibling duo in Hollywood to both come out as transgender, the Wachowski sisters' journey is not entirely unique.
"There is a biological component," to being transgender, Dr. Colt Keo-Meier, a clinical psychologist who also sits on the board of directors for the World Professional Association for Transgender Health, tells PEOPLE. "However, it is not 100 percent genetic, because we do have plenty of cases of identical twins, where one of them is transgender and the other one is not. If it was 100 percent genetic, both of them, because they share the same DNA, would be expected to be transgender."
Keo-Meier says some identical twins may include one sibling who identifies as transgender and another sibling who identifies as gay or bisexual.
"We don't exactly know all the things that are going on, but we think there's a complex interplay of multiple different biological interactions that are related to being transgender," Keo-Meier said.
The Wachowskis are two years apart: Lana is 50 and Lilly is 48. They became famous for co-directing the Matrix trilogy, and went on to co-write V for Vendetta and direct Cloud Atlas.
Overall, Keo-Meier says one sibling coming out as transgender can sometimes help ease the transition for another sibling.
"It depends on the nature of the relationship between the siblings before coming out and then it also depends on who comes out first and how they were received when they came out," Keo-Meier said. "In the case where siblings have a close relationship and one comes out first, that might be really the catalyst that gets the other sibling to start thinking about their own gender identity and maybe coming to that realization. Or, maybe they have already been on that journey, questioning, exploring and figuring out their gender identity, and their sibling comes out and they might have that sense of, 'Oh, me too. Wow!' "
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Keo-Meier says the media plays a major role in the portrayal and understanding of transgender identity. In a statement she wrote to the public and published in Windy City Times, Lilly talked about a reporter coming to her door and asking about her gender identity.
"I knew at some point I would have to come out publicly," she wrote. "I just wanted – needed some time to get my head right, to feel comfortable. But apparently I don't get to decide this."
Keo-Meier says any pressure to publicly identify as transgender is unacceptable.
"I see it as an ethical violation in the deepest sense and we really need to stop forcing people to come out because of the media," he says. "That's really, deeply personal and incredibly problematic and each person should have their own agency to decide when and if they're going to disclose their transgender identity."
As for what the Wachowskis' coming out means to the LGBT community?
"I think it depends on how the media portrays this and how respectfully it is communicated, but I would say that, in general, when people out and tell their stories, it is helpful," he said. "It is helpful for other transgender people to realize they're not alone. It is helpful for families who are coming to terms with what it means to have a transgender family member."