BackgroundAs sequencing technology has advanced in recent years, a series of synapse-related gene variants have been reported to be associated with autism spectrum disorders (ASDs). The α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor is a subtype of the ionotropic glutamate receptor, whose number or composition changes can regulate the strength and plasticity of synapses.Case presentationHere, we report a de novo GRIA2 variant (NM_001083619.3: c.2308G > A, p.Ala770Thr) in a patient with obvious behavior regression and psychiatric symptoms. It encodes GluA2, which is the crucial subunit of the AMPA receptor, and the missense variation is predicted to result in instability of the protein structure.ConclusionsThe association between GRIA2 variants and onset of ASD symptoms is rare, and our study expands the spectrum of phenotypic variations. For patients with an unexplained etiology of ASD accompanied by psychiatric symptoms, genetic causes should be considered, and a complete genetic evaluation should be performed.