In this paper, we present a general method for constructing finite-dimensional quasi-Hopf algebras from finite abelian groups and braided vector spaces of Cartan type.The study of such quasi-Hopf algebras leads to the classification of finite-dimensional radically graded basic quasi-Hopf algebras over abelian groups with dimensions not divisible by 2, 3, 5, 7 and associators given by abelian 3-cocycles. As special cases , the small quasi-quantum groups are introduced and studied. Many new explicit examples of finitedimensional genuine quasi-Hopf algebras are obtained.