\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{equation}
A=\left\{\vrule height 11mm width 0pt\right.\!\!\!
\begin{array}{l}
\dfrac BC,\\[4mm]
\dfrac DE,\\[4mm]
\dfrac FG.
\end{array}
\end{equation}
\end{document}