Since I didn't get a response back from you, I wanted to make sure you know to find out about my African gggrandma, I am a direct line descendant so I used my DNA and a discounted price given to attendees at an African American Genealogy conference in DC one year. I am 99.7% African descended. This was before Dr Kittles was showcased on TV doing Whoopi and Oprahs DNA.
23andme is offering a FREE kit that is about dna of blacks health. Try ordering this. Where it says type in the promotion code-- after typing in the code they give you to use QDPEBG, hit ENTER not apply. It will take you to the free site. I just learned that. Maybe we will bump heads again--finding these VANCE descendants. Good Luck