Groups with maximum vertex degree commuting graphs

Let G be a finite non-abelian group and Z(G) its center. We associate commuting graph $$\Gamma (G)$$ to G, whose vertex set is $$G\setminus Z(G)$$ two distinct vertices are adjacent if they commute. In this paper we prove that the of all groups has maximum degree bounded above by fixed $$k \in {\mathbb {N}}$$ finite. Also, characterize for which associated graphs have at most 4.