Binomial edge ideals and rational normal scrolls

‎Let $X=left(‎ ‎begin{array}{llll}‎ ‎ x_1 & ldots & x_{n-1}& x_n\‎ ‎ x_2& ldots & x_n & x_{n+1}‎ ‎end{array}right)$ be the Hankel matrix of size $2times n$ and let $G$ be a closed graph on the vertex set $[n].$ We study the binomial ideal $I_Gsubset K[x_1,ldots,x_{n+1}]$ which is generated by all the $2$-minors of $X$ which correspond to the edges of $G.$ We show that $I_G$ is Cohen-Macaulay‎. ‎We find the minimal primes of $I_G$ and show that $I_G$ is a set theoretical complete intersection‎. ‎Moreover‎, ‎a sharp upper bound for the regularity of $I_G$ is given‎.‎