The major proteins of synaptic dysfunction involved in the pathogenesis of AD are neurogranin (Ng), synaptosomal-associated protein 25 kDa (SNAP-25), soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE complex), synaptotagmin, syntaxin, Ca2+, complexins-I/II (CPLX1/2) (GABAergic/glutamatergic selectively expressed proteins). This evidence concerns the gene NRGN and Alzheimer disease.