Background:The C-terminal rhodopsin mutation Ter349Glu causes rapid degeneration in humans. Results:Ter349Glu rhodopsin, with an additional C-terminal 51 amino acids, activates normally but is defective in subcellular localization. Conclusion:Loss of proper rod outer segment morphogenesis likely contributes to the severe human phenotype. Significance:The results point to a likely pathogenic mechanism for one of the most severe forms of hereditary retinal degeneration. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc.