I just found the MacIsaac results you mentioned at YSearch and compared them with the Frame A modal haplotype - hence the follow-up. The genetic difference is 9 over the 67 markers, so a common ancestor would be way back in time. More importantly, MacIsaac doesn't carry the trademark RecLOH mutation YCAIIa,b=21,21 carried by all of the men in the Frame A group (they are the nearest matches to your MacIsaacs). Frame is pretty much a Lowland surname, and as said in my previous post, there is only the one Isack Frame mentioned in the old parish registers. The Frames are proving to be a reasonably closely related bunch, so if the Isack Fram in Inverness was in any way related to your MacIsaacs, the results would suggest his particular Frame line, if it doesn't have the RecLOH mutation, would be quite distinct from the main Frame A group, and also the others in the Project thus far. Interesting scenario!