A rep for Charlie Sheen is talking to ET about the actor's son's medical condition.

As ET was first to report, one of Charlie and wife Brooke Mueller-Sheen's newborn twin sons, Max, is still in the hospital with a heart condition.

While a source tells ET definitively that baby Max does have a heart condition, the reason he is still hospitalized is due to his low birth weight.

A rep for Charlie told ET Thursday: "The Sheens appreciate the outpouring of concern but have assured everyone that both Bob and Max are fine."