Shauna Harrison writes about using 23andMe and finding 29 siblings all from the same donor dad and what it's like to meet strangers with whom you share so much DNA.

Working with the Yale Genetics Club, 23andMe helped to sponsor the screening of the film Thank You for Coming, a new documentary by Sara Lamm about genetic testing for someone who is a donor-conceived child.

In the best children’s stories the parents are done away with early on.Mom or dad – sometimes both of them – are dead and gone even before the opening “once...