Jews that converted out of fear for the inquisition often
took on an overly christian sounding name inorder to 'apease' the church.
So it could be true. Although i saw a documentary suggesting that Columbus hid his past as he was from Catalonia, which would not make him popular in Spain.
(Despite Catalonia now officially part of Spain)
http://www.barcelonareporter.com/index.php/news/comments/3798/
From Discovery Channel: ‘Spanish Saliva May Reveal Real Columbus’ | “Hundreds of saliva samples may reveal the disputed origins of Christopher Columbus, according to a genetic investigation aimed at finding possible distant descendants of the admiral's family.
A team of geneticists, led by José Antonio Lorente Acosta from the University of Granada, has begun to collect samples from Spanish men sharing the surname Colón (Columbus) in the effort to find a common ancestor who may be the link with the man credited for discovering the New World in 1492.
Columbus is widely thought to have been born in 1451 in Genoa, Italy, the son of wool trader Domenico Colombo and Susanna Fontanarossa.
Other theories, however, argue that the explorer was born in Spain, his real name being Cristóbal Colón.
Various versions of the story have Columbus as a pirate born in Catalonia, a Catalan Jew who fled to Genoa to hide from the Spanish Inquisition, and the illegitimate son, born in Majorca, of Spain's prince of Viana.
Already 300 Spanish volunteers have agreed to take part in the genetic study. The search will be conducted in Catalonia, Majorca and Valencia; samples will be also taken in Genoa.
The DNA of hundreds of men sharing Columbus' surname will be then compared to DNA from the bones of Hernando - Columbus' son through an extramarital affair - whose identity is certain.
"If we find a chromosome (which males inherit through the paternal line) we could say they were related," Acosta told reporters.
It will not be an easy task: in Catalonia alone, there are about 2,000 Colóns in the electoral register.”