This theory makes no sense. If a "Colom" was trying to hide his identity, why would he choose to be known with the name Columbus? And, why did his true identity become known once he had become famous?
DNA may expose the shady origins of Columbus (excerpt)
About 120 Catalans are to donate samples of their saliva this week to a team of geneticists headed by José Antonio Lorente Acosta, the head of the laboratory of genetic identification at Granada University.
Tests on another 180 people sharing the name Colom will follow in Mallorca and Valencia. Investigators will compare the results with the DNA from Columbus's illegitimate son, Hernando, whose remains lie in Seville Cathedral.
"We're not looking for descendants of Columbus but a common ancestor who may be the link between the admiral and today's Coloms. If we find a Y chromosome (the only one that males inherit by the paternal line), we could say they were related," a spokesperson for Acosta said this week.