I suspect that was his Hollywood name. He looked Italian.
Darren, born James Ercolani, was born in Philadelphia in 1936. His parents were Italian immigrants, and he spent more time getting into trouble outside school then hitting the books.
Yep; from the same South Philly Italian-American neighborhood as Frankie Avalon. Darren's real surname was Ercolani. Frankie's was Avalone. Mostly southern Italian descended folks, Sicilians and Neapolitans and some Abruzzese, lived there in the 50s and many still do.