Brave teen's love of singing is her only escape from mystery illness

A seriously ill teen who dreams of a career on Broadway but could die if she sings in public says recording covers for the internet is her only escape.

Serena Schwerdfeger (corr), 19, has the voice of an angel but is prevented from showcasing it on stage due to a mystery condition that rules her life.

The aspiring star lives with a primary immune disease which doctors have been unable to diagnose as she exhibits characteristics from four different illnesses.