Zach Roloff and Tori Roloff‘s are opening up about their newborn son’s diagnosis, which comes weeks after his arrival.

In an interview with Us Weekly, published May 25, the stars of Little People, Big World, who welcomed Josiah in late April, shared he has achondroplasia, a type of genetic condition. But as the couple noted, his achondroplasia doesn’t define him. “He’s a boy with achondroplasia,” Zach told the outlet. “It’s not his identity.”

According to Johns Hopkins Medicine, achondroplasia is a form of skeletal dysplasia that can lead to a shorter stature, with the organization noting “adult height in people with achondroplasia is between 42 and 56 inches.” 

As Zach and Tori shared, several of their family members—including their kids Jackson Roloff, 5, and Lilah Roloff, 2, and his mom Amy Roloff—have achondroplasia. Zach’s dad, Matt Roloff, has Diastrophic dysplasia.

“We have so many resources,” Tori said, “and there’s a lot of parents out there who don’t have the same confidence that Zach and I do.” And, as the TLC stars noted, they intend to continue to use their platform to be advocates for people with achondroplasia.