Never mind 150 half-siblings: Try ‘twinblings,’ inadvertent full siblings from different mothers

I’ve heard a fair amount of “woahs” about a story in yesterday’s New York Times noting that one sperm donor seems to have fathered 150 half-siblings. (The Times has trod this ground before.)

The reaction reminded me that I’d come across a paper earlier this summer in the journal Fertility and Sterility. The case report, by fertility doctors in the Bronx and Westchester, begins as follows (emphasis mine):