Check the lines of Nicholas ADAM and Juliana Barnhardina SCHWEICKHARDT .. I believe they have an Isaac in Berks.This is the line that has Bernhardt ADAM as in the Johannes Bernhardt ADAM Burying Grounds in West Reading, Berks Co, PA
Another line in the area is the Anthony ADAM(S) line but not sure if they have an Isaac. They started in Perry/Windsor, Berks Co, PA .. There is also a Caspar ADAM who started in Philadelphia Co, then Berks and then Northumberland Co.