documentclass{scrbook}
usepackage{hyperref}
usepackage[toc,acronym,nopostdot,nomain,style=alttree,shortcuts]{glossaries}
  setacronymstyle{long-sc-short}
  makeglossaries
  newacronym{sma}{sma}{SubMiniature version A}
begin{document}
  a ac{sma}\ % gives "a SubMiniature version A (SMA)"
  a ac{sma}   % gives "a SMA"
end{document}