"Able"? Well, as it apparently happened, the technical answer is "yes." You appear to actually be asking what you can do about it. Insufficient details are provided to do a full analysis, but an initial question is jurisdiction. You do not say how long the child spent with his uncle, or who lived where (in what State) during and prior to that time, for how long. All of that is relevant to figuring out who can do what, and where it must be done.
First, create a timeline going back to the birth of the child to answer that question (a guide for doing so is posted on http://willicklawgroup.com/consultation-policies/. Then consider substantive jurisdiction, to figure out in what State you need a good Family Law specialist. A primer is "The Basics of Family Law Jurisdiction" posted at http://willicklawgroup.com/child-custody-and-visitation/. A lot of other useful information is posted there as well.
Then get to a well-informed family lawyer in the appropriate place, and do so soon -- you are going to require a more detailed analysis, and evaluation, than can be done by email.
Answered on Nov 22nd, 2014 at 2:34 PM