Gia studied Biochemistry as an undergraduate at the University of California, Santa Cruz. She then moved to Yale University and obtained a Ph.D. in the lab of Joan Steitz. Following her graduate studies she joined the lab of Tom Rapoport at Harvard, where she studied the mechanisms that define the elaborate shape of the endoplasmic reticulum. In 2006, Gia started her own lab at the University of Colorado, Boulder. In 2018, Gia was named Howard Hughes Medical Institute Investigator.