Mutations in GRIN2A and GRIN2B encoding regulatory subunits of NMDA receptors cause variable neurodevelopmental phenotypes.

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Citation

Endele S, Rosenberger G, Geider K, Popp B, Tamer C, Stefanova I, Milh M, Kortum F, Fritsch A, Pientka FK, Hellenbroich Y, Kalscheuer VM, Kohlhase J, Moog U, Rappold G, Rauch A, Ropers HH, von Spiczak S, Tonnies H, Villeneuve N, Villard L, Zabel B, Zenker M, Laube B, Reis A, Wieczorek D, Van Maldergem L, Kutsche K

Mutations in GRIN2A and GRIN2B encoding regulatory subunits of NMDA receptors cause variable neurodevelopmental phenotypes.

Nat Genet. 2010 Nov;42(11):1021-6. doi: 10.1038/ng.677. Epub 2010 Oct 3.

PubMed ID
20890276 [ View in PubMed
]
Abstract

N-methyl-D-aspartate (NMDA) receptors mediate excitatory neurotransmission in the mammalian brain. Two glycine-binding NR1 subunits and two glutamate-binding NR2 subunits each form highly Ca(2)(+)-permeable cation channels which are blocked by extracellular Mg(2)(+) in a voltage-dependent manner. Either GRIN2B or GRIN2A, encoding the NMDA receptor subunits NR2B and NR2A, was found to be disrupted by chromosome translocation breakpoints in individuals with mental retardation and/or epilepsy. Sequencing of GRIN2B in 468 individuals with mental retardation revealed four de novo mutations: a frameshift, a missense and two splice-site mutations. In another cohort of 127 individuals with idiopathic epilepsy and/or mental retardation, we discovered a GRIN2A nonsense mutation in a three-generation family. In a girl with early-onset epileptic encephalopathy, we identified the de novo GRIN2A mutation c.1845C>A predicting the amino acid substitution p.N615K. Analysis of NR1-NR2A(N615K) (NR2A subunit with the p.N615K alteration) receptor currents revealed a loss of the Mg(2)(+) block and a decrease in Ca(2)(+) permeability. Our findings suggest that disturbances in the neuronal electrophysiological balance during development result in variable neurological phenotypes depending on which NR2 subunit of NMDA receptors is affected.

DrugBank Data that Cites this Article

Polypeptides
NameUniProt ID
Glutamate receptor ionotropic, NMDA 2BQ13224Details
Glutamate receptor ionotropic, NMDA 2AQ12879Details