Gleanings from the Weekly Genealogist…
The Atlantic had an article on the King’s Daughters or Filles de Roi. French genealogy in Quebec is so well documented that professional geneticists and demographers use it for their research.
One of the mutation’s they’ve found is Leber’s hereditary optic neuropathy. It causes vision loss mostly in young men. The University of Montreal traced the ancestry of 11 modern day patients back to one woman. Her mutation is responsible for 89% of Leber’s cases in Quebec. It’s called “mothers curse”.