De Novo Variants in GRIA4 Lead to Intellectual Disability with or without Seizures and Gait Abnormalities

Using trio whole-exome sequencing, we have identified de novo heterozygous pathogenic variants in GRIA4 in five unrelated individuals with intellectual disability and other symptoms. GRIA4 encodes an AMPA receptor subunit known as GluR4, which is found on excitatory glutamatergic synapses and is important for learning and memory. Four of the variants are located in the highly conserved SYTANLAAF motif in the transmembrane protein M3, and the fifth is in an extra-cellular domain. Molecular modeling of the altered protein showed that three of the variants in the SYTANLAAF motif orient toward the center of the pore region and most likely lead to disturbance of the gating mechanism.

Source: The American Journal of Human Genetics - December 7, 2017 Category: Genetics & Stem Cells Authors: Sonja Martin, Adam Chamberlin, Deepali N. Shinde, Maja Hempel, Tim M. Strom, Allison Schreiber, Jessika Johannsen, Lilian Bomme Ousager, Martin J. Larsen, Lars Kjaersgaard Hansen, Ali Fatemi, Julie S. Cohen, Johannes Lemke, Kristina P. S ørensen, Katheri Tags: Report Source Type: research