People with Down syndrome have an extra copy of chromosome 21. This can cause children with Down syndrome to develop more slowly. But that doesn't mean every area of their development is affected.
And while it may be the first time a Gerber baby has Down syndrome, Lucas is far from the first person with Down syndrome to be in the spotlight.
But despite these notable figures and plenty of other celebs, parents and people with Down syndrome sharing messages online, there still seems to be a lot of misunderstanding and even fear of people with Down syndrome.
Remember this father's emotional message about what people get wrong when explaining what Down syndrome is?
"Down syndrome is literally one of the most beautiful things that's ever happened in my life. ... It's not an illness; it's not an illness," Robb Scott said.
The Centers for Disease Control and Prevention says 1 in 700 babies in the U.S. are born with Down syndrome.