How One Woman Brought the ‘Mother’s Curse’ to Thousands of Her French-Canadian Descendants

The first King’s Daughters—or filles du roi—arrived in New France in 1663, and 800 more would follow over the next decade. Given their numbers, they were not literally the king’s daughters of course.

They were poor and usually of common birth, but their passage and dowry were indeed paid by King Louis XIV for the purpose of empire building: These women were to marry male colonists and have many children, thus strengthening France’s hold on North America. French Canadians can usually trace their ancestry back to one or more of these women.

For more information about the filles du roi, see my earlier article at http://bit.ly/2wG6ecP.

Whenever a small group of people leave a large population (France) to found a new one (New France), they bring with them a particular set of mutations. Some of these mutations will by chance be more common in the new population and others less so. As a result, some rare genetic disorders disproportionately impact French-Canadians.

One of these is Leber’s hereditary optic neuropathy, which causes vision loss, usually in young men. Recently, geneticists using French Canadian genealogy have reexamined the effects of Leber’s and found a striking pattern of inheritance: It seems to show a long-theorized but never-seen-in-humans pattern called the “mother’s curse.”

Leber’s hereditary optic neuropathy is passed down from mothers to sons and daughters alike but the daughters rarely suffer from the problem themselves. It seems to affect men eight times more often than women. Also, men never pass it to their children. If you suffer from Leber’s hereditary optic neuropathy, you inherited it from your mother’s mother’s mother’s mother’s female ancestors and back through the all-female line to France. Although this condition usually begins in a person’s teens or twenties, rare cases may appear in early childhood or later in adulthood.

If you have French-Canadian ancestry on your mother’s side of your family tree, you will want to read about Leber’s hereditary optic neuropathy in an article by Sarah Zhang in The Atlantic web site at: http://theatln.tc/2jKkXSR. However, the article focuses primarily on the method by which the neuropathy is passed down from one generation to the next. For more specific information about the effects of the disease, see Wikipedia at https://en.wikipedia.org/wiki/Leber%27s_hereditary_optic_neuropathy and dozens of other online articles by starting at http://bit.ly/2hg4816.