Itemize with cases in beamer

Question

I'm working on a beamer presentation in LaTeX and I'm trying to mix somethings that don't seem to want to go together. I'm trying to combine itemize and cases. Here is what I've tried and it didn't work:

\begin{frame}
\begin{itemize}
    \begin{rcases*}
    \item X
    \item Y
    \item Z
    \end{rcases*} These are letters\\
\item 1 $rightarrow$ One
\item 2 $rightarrow$ Two
\item 3 $rightarrow$ Three
\end{itemize}
\end{frame} 

The issue is that I can't seem to combine everything smoothly. I can either itemize or put things into the case. Any suggestions?

Answer 1

Here is a solution with blkarray: it consists in nesting an itemize (correponding to the first thee items) in a blockarray environment, the rest in another itemize, and a suitable negative vertical spacing between both environments:

\documentclass{beamer}
\usepackage{blkarray}

\begin{document}

\begin{frame}
  \begin{blockarray}{@{}p{2cm}\Right{\}}{These are letters}}
    \vspace{-\baselineskip}
    \begin{itemize}%[nosep, before = \vspace*{-0.6\baselineskip},after= \vspace*{-0.86\baselineskip} ]
      \item X
      \item Y
      \item Z
    \end{itemize}\vspace*{-\baselineskip}
  \end{blockarray}
  \begin{itemize}\vspace*{-\dimexpr\topsep + \baselineskip-\itemsep }
    \item 1 $\rightarrow$ One
    \item 2 $\rightarrow$ Two
    \item 3 $\rightarrow$ Three
  \end{itemize}
\end{frame}

\end{document}