Treatment recommendations/therapies? (Please help!!)

So, I’m actually writing this on behalf of a friend—he isn't exactly a tech person, so I figured I'd handle the typing part. He has a four-month-old baby who was actually flagged for some limb irregularities as far back as the prenatal ultrasounds. It’s a complex situation: the right arm lacks an elbow entirely, ending instead in just two small protrusions where fingers should be. On the other arm, there is an elbow, but it’s non-functional—it doesn't move at all. Then, on the left hand, there’s no palm, just three fingers. The doctors mentioned they saw these issues during the pregnancy scans, but that’s about as much info they’ve provided. I’m trying to find out if there are any specialists—anywhere in North America or even globally—who focus on specific therapies or perhaps advanced prosthetics? We're particularly interested in whether there's anything that could help with the left elbow, maybe through targeted therapy, to see if we can eventually coax some kind of movement or function out of it.

Truly appreciate any insight you all might have! Best regards!