Bloodwise, yes. There was a son, Assène, who married Bertha Hussa. He adopted his stepson (age 19) who was renamed Wilhelm von Hartenau. Wilhelm had 3 children: 1.Alexander Assène Franz von Hartenau b. 28 Sep 1942; 2.Elisabeth Franziska Maria von Hartenau b. 4 Jun 1945; 3.Franziska Vera Maria von Hartenau b. 2 Mar 1948. Wilhelm was an MD. I wonder as the only 'descendants' if the family is in possession of much of the material on the lives of Alexander and Johanna.