Born This Way: Rare Form of Dwarfism Sets Girl Apart From Twin Sister

Meet Sierra and Sienna Bernal – 12-year-old twins from Texas. They both have blonde hair, enjoy shopping and like acting and singing.

But that’s where the similarities end.

Sierra is just over 5 feet tall and weighs 78 pounds; Sienna – or Sinny as she likes to be called – is just under 4 feet tall and weighs just 28 pounds.

The girls are the only twins in the world where one – Sinny – is a primordial dwarf.

In fact, Sinny was so small during her mother Chrissy’s pregnancy, doctors didn’t even know she was pregnant with twins until her sixth month – and she delivered them one month later.

Sinny weighed only a little more than a pound when she was born, and she had a host of other health problems: a hole in her heart, part of her brain was missing (this is known as Dandy Walker syndrome) and chronic lung disease.

Sierra weighed a little more than 4 pounds and, for all intents and purposes, was born healthy.

Still, Sinny’s health problems offered no clues to primordial dwarfism, and it wasn’t until she was 6 years old that the family was given a diagnosis.

“We went to a geneticist, and at that point… what was one more doctor,” said Chrissy, who writes children’s books, including “Sienna’s Locket” and “Living Life Sinny-Sized.” (She keeps a blog of the same name).

“He looked at her, and he said, ‘we have someone who could help.’ It was a visiting doctor from Belgium, who said he had seen two (children) just like her. He ran some tests, and verified she was a primordial dwarf.”

It is believed there are fewer than 200 primordial dwarfs worldwide, according to the Potentials Foundation, a non-profit organization dedicated to helping families with PD. Individuals who have PD usually reach their maximum height around the age of 12 – so Sinny is likely not going to grow any taller. And PDs often have skeletal, dental, vision and/or hearing issues.

There are currently five different sub-types of primordial dwarfism, but doctors believe Sinny may have a type that has yet to be identified. Geneticists at the Scottish Rite Hospital in Dallas, Texas, are studying Sinny’s genes and are hoping to find where the mutation happened and what type of primordial dwarfism she has.

Sinny, whose heart was fixed when she was just a few months old, wears glasses, unlike her sister, and has hearing aids, because the bones in her ears are so small.

But she has a smile – and a sense of humor – that is 10 times bigger than her tiny frame.

When asked what it’s like to be a twin, she replied, “It’s awesome. You can look at your twin and see if an outfit is going to look good on you.” (Laughing). “Also, it gives you an automatic buddy. If you have no one to talk to, you can talk to your twin.”

Sierra, always the “big” sister, is protective of her sister, Chrissy said, especially if someone dares to make a comment about Sinny.

But she knows the situation has impacted Sierra in ways that are challenging; forcing her to grow up quicker than she should have.

“Being Sienna’s twin is pretty cool,” Sierra said. “It makes me even more special. Being Sienna’s twin has made me a strong person. Plus, I can pretty easily see who my real friends are because Sienna and I are a packaged deal. If you don’t like her because she’s different, then you don’t get me.”

Sierra worries though – they are at an age when boys and dating are becoming increasingly important – and she doesn’t want her sister to get left behind.

“She’s pretty popular,” Chrissy said of Sinny, who is going through puberty like any other pre-teenager. “But it’s getting to the harder age where she feels more comfortable with younger children. Younger children aren’t as judgmental. They have separate friends.”

The girls’ father, Joey, and their brother, Austin, who is 16, round out the Bernal family, and they all keep a positive outlook on life.

They use each new challenge as a teaching tool for their children, and while they are unsure what the future holds – they said they just take things “day by day.”