Yes, there can be a "genetic" element to AF. That does not however indicate incurability. The conflicts of our ancestors do affect us. Discovering their conflicts frees us and our ancestor.
PTSD is not longer the dreaded incurable malady is was in the past. The new "energy" therapies sprouting all about make quick work of PTSD. If your ancestor had PTSD it will affect you.
Dr. F. Shapero discovered EMDR and began using it on war veterans, some of whom had been treated with conventional psychotherapy for decades. She accomplished in a few sessions what others took a life time, if ever to accomplish.