My identical twin has dwarfism so you’d better not mess with her

These twins are identical — but one is half the size of the other.

Sienna Bernal and Sierra Bernal are 20-year-olds from Tomball, Texas, who share one major difference: Sienna was born with primordial dwarfism.

She stands more than a foot shorter than Sierra, and she weighs only 50 pounds, in comparison to her sister’s 98 pounds.

“Whenever people find out we’re twins, they’ll ask, ‘How old is she?’ ” Sierra, an aspiring singer-songwriter, tells Barcroft Studios. “So a lot of times, even after you’ve established that we’re twins, they’ll ask Sienna if she’s younger. I’m like, ‘That’s how twins work — we’re the exact same age.’ ”

The Bernal sisters are the only known instance of female identical twins with a primordial dwarf in the pair, ABC News reports. Dwarfism is generally defined as an adult height of 4 feet 10 inches or less, according to the Mayo Clinic.

Sienna was also born with Dandy-Walker syndrome, which causes abnormal brain growth. She weighed just 1 pound 7 ounces at birth and was nearly six weeks behind her sister in development.

Today, the unabashed “mermaid fan” is an avid swimmer who is writing a book about her life. She admits it irks her when clueless strangers treat her like a child — but she knows how to handle them.

“Sometimes they think Sierra is my older sister and they treat me differently,” Sienna says with a wide, knowing smile. “I’m not a child. Let’s clarify that, people. When they talk to me like a kid, they’ll be like, ‘How are you?’

“I’m like, ‘I am fine — I am 20 years old.’ ”

Their mom, Chrissy Bernal, says doctors told the family Sienna had a 10 percent chance of surviving past 24 hours, and “if she did make it out of the hospital, they said she would most likely be a vegetable.”

Two decades later, and despite major physical differences, the sisters say they are just as close as any other identical twins, supporting each other through everything.

“They have the sibling bond, like normal siblings do — but being twins, they’re definitely closer,” says Chrissy, 41. “You can see it if they’ve been separated during the day. They will immediately come together, and you can tell they really did not like not being together.”

Sierra admits to being “extremely protective” of Sienna, which she thinks has “made her a little sassier because she knows Sierra is going to take care of it if there’s a problem.”

Culled from nypost.com