Kristi Smith did not want to undergo the stress and heartache of trying to have a biological child with her rare genetic condition. Instead, she adopted and saved four other kids who suffer from the same disorder.

Smith was diagnosed at birth with Phenylketonuria (PKU), a condition that can lead to seizures, developmental disabilities, and mental and physical disorders if it is not treated properly.

Her parents discovered that they could keep the condition in check by keeping their daughter on a restrictive low-protein diet. Thanks to a special dietary formula that Smith drank on a regular basis, she was able to finish high school, graduate with two college degrees, and settle down with her husband Matt in Tucson, Arizona.

When they started talking about having kids, however, the odds were not in their favor. Smith's online research showed that trying to give birth with PKU often ended with fetal abnormalities and miscarriages.

Upon researching the possibility of adoption, Smith found two children in China who also had PKU.

"I didn't want to potentially go through all that headache and heartache and stress when there are kids who need a family out there," said Smith, according to TODAY. "We loved the idea of giving a home to a kid with PKU because we know how to take care of it. When I told my husband about [these little boys], he said, ‘Are we going to China?'"

In May 2015, Kristi and Matt brought home their two new adoptive sons, Andrew and Luke.

The boys, both of whom were two years old at the time, had been raised in an orphanage that understood PKU and cared for the condition. Andrew and Luke were smart, curious, and energetic youngsters.

Then, Kristi heard about two more kids with PKU in China. A boy named Ben, who had not been as nurtured as Andrew and Luke, was 13 years old at the time. Once he turned 14, he would be considered "unadoptable" and turned out onto the streets. Additionally, the lack of treatment for his PKU caused him to have some developmental delays, among other issues.

The Smiths flew to China once more and adopted Ben and a 9-year-old named Caleb.

Now, the four of them are a happy, thriving family.

"We drink our formula together," said Smith. "We tell them it helps them to be smart and to learn things. And, we tell them without it, our brains will get sick."

"They came to us not knowing how to go up stairs or how to run and jump — they were overwhelmed, but now they are just flourishing," she said. "They're becoming kind and courteous, and it's just like a lightbulb went on for everything — from them understanding their PKU to all of their school and academic things."

Click To Share The Sweet Story With Your Friends – Photos by Kristi Smith