This is way more common than people realize. Anyone can claim to graduate from anywhere. If top company executives and congressmen have been caught lying about their degrees, you can be sure that a large chunk of the regular population does it as well.
In a similar vein, Elizabeth Warren claimed to be Native American although DNA testing showed she had a statistically insignificant amount of Native American DNA.
Is it? I don't think DNA plays into who people elect/hire as much as a college degree. Also, people know which college they went to. People generally don't know what % of their DNA is Norwegian.
As a person with a degree from a UK university that got married and changed her last name, never have I ever passed a background check for university education.
Couple of companies asked me for a copy of my diploma, I just kindly reminded them that I am old and I moved many countries since graduation