When Sister Wives’ Maddie Brown Brush and her husband Caleb discovered they were pregnant with

their second child, doctors informed the couple that their unborn baby would be diagnosed with

oligodactyly, a congenital anomaly marked by the presence of fewer than five fingers on a hand.

However, once they welcomed daughter Evangalynn Kodi, the newborn was also missing a thumb, a toe, and one of her fibulas, according to an exclusive with People. In addition, two of her fingers were fused together.

Doctors then diagnosed Evangalynn with fibular aplasia, tibial campomelia, and oligosyndactyly (FATCO) syndrome.

FATCO syndrome is an incredibly rare genetic disorder that affects the formation of a baby’s bones when they’re in utero. There is no known cause behind the diagnosis, and because of the disease’s rarity, it’s unclear how the Brush’s new daughter’s future will look.

When Brown Brush went in for a routine ultrasound, her appointment, which should have taken less than an hour, lasted for over two hours. Immediately, she knew something was wrong.

“It usually takes about 45 minutes, but the doctor just kept looking and looking,” Brown Brush told People. “I was stressing out the whole time.” She recalls that the doctor finally met them in his office and revealed to the pregnant mother that he couldn’t find all 10 fingers, so he would be diagnosing her with oligodactyly.

At the time, she was relieved because she knew a lot more could have gone wrong.

Still, when Evangalynn was born on August 20, the doctors and the couple knew there were more issues. The couple was shocked when they heard the official diagnosis. “I was just sitting there trying to comprehend what’s going on, having just had a baby as they are bringing in all these specialists. I was freaking out,” the TLC star said.

Maddie Brown Brush, the daughter of Sister Wives’ Janelle and Kody Brown, told People that while she initially wanted to protect her daughter’s privacy, she didn’t want Evangalynn to feel ashamed about her own condition.

Instead, she wanted to ensure that her daughter would feel proud of her differences as she gets older. Just as her family celebrates their differences on the TLC show, Maddie wants her child to be proud of who she is and where she comes from.

Caleb and Maddie were married in June 2016, and their ceremony was officiated by Maddie’s father and the patriarch of the Brown family, Kody Brown (via Us Weekly). Despite the famous polygamous family, the Brushes are not living what they call “plural marriage.”

Caleb told People in 2015 that although the couple “supports Maddie’s family with their choice,” he and Maddie would remain in a monogamous marriage.

While congenital limb deficiencies like extra fingers or under-grown extremities aren’t uncommon in newborns, FATCO syndrome occurs in less than one out of every 1 million births (via Orphanet).

There is little information on how the syndrome is treated, but usually, surgery and amputations are used to help better the quality of the child’s life.

Maddie revealed that because Evangalynn is still very young, the family will have to wait before they can start any kind of treatment or surgeries until she turns 1 year old. By then, her body will be more developed and the parents can decide on the next steps in the baby’s treatments.

“How will she be at 70 years old? Will this come back and haunt her? There’s still a lot of unknowns, which is hard,” Brown Brush explained.

Maddie did open up in a recent Instagram post about the situation, saying, “This is one of the hardest things that Caleb and I have gone through and the decision to share almost as difficult, but after a lot of consideration, we realized that it’s the best thing for our daughter and there is a chance it may help other parents who may also be struggling…”

Despite the diagnosis, the couple are still thrilled to have a new addition to their family. Maddie continuously shares photos and videos on her Instagram of her new baby as well as the couple’s son, Axel James, who is 2 years old.

“Axel is doing really good as a big brother,” said Caleb in an interview with TLC. “He loves Evangalynn. He doesn’t want to let her go, but at the same time he wants to start playing with her. So, it lets me know that as a parent we are doing something right.”

When it came to deciding on the baby’s name, they looked to their family for inspiration. “We were trying to think of a family name. [Caleb’s] grandma’s name was Eva, my mom’s name is Janelle, and his mom’s middle name is Lynn, so we just put it all together and did Evangalynn.”

They also decided to select Kodi as the child’s middle name in honor of Maddie’s father.

It’s heartwarming to know that the Brush family isn’t letting this diagnosis get in the way of letting Evangalynn live a full and purposeful life.