This invention provides UNA oligomers for selectively inhibiting V30M TTR expression, which can be used in treating amyloidosis. The UNA oligomers can have a first strand and a second strand, each of the strands being 19-29 monomers in length, the monomers being UNA monomers and nucleic acid monomers. Embodiments include pharmaceutical compositions and methods for treating or preventing TTR-related amyloidosis by administering a UNA oligomer to a subject.