As of this date, R' AJ Heschel has 19 living yDNA descendants listed in GENI, the most recent born in 1984. yDNA testing of one or more of these descendants would be a valuable addition to this family tree's knowledge base. If a person reading this is qualified to make the test and is willing to do so, please reply to this discussion.
Avi Kolan I am not sure of this information. If you want to look into the trees GENI uses to create the living yDNA descendant list you can easily do so by highlighting on the DNA tab on this profile and then selecting under YDNA 'View a List of Living People..." From the list you can access the pedigree tree of each person on the list and follow it up to where you want to investigate. Best Wishes, Adam