A de novo missense variant in the CAMK2A gene (c.548A>T;p.Glu183Val) was identified in an ASD proband from the Simons Simplex Collection in Iossifov et al., 2014; additional functional characterizaton in Stephenson et al., 2017 demonstrated the p.Glu183Val missense variant disrupted multiple CaMKII functions, induced synaptic deficits and caused ASD-related behavioral alterations in mice. A de novo intronic variant adjacent to the splice donor site of the CAMK2A gene was identified in another ASD proband from the Simons Simplex Collection in Iossifov et al., 2014; in silico analysis performed in Kury et al., 2017 predicted that this variant resulted in skipping of in-frame CAMK2A exon 8 and a partial loss of the CAMK2A kinase domain. Kury et al., 2017 reported an additional 12 individuals with intellectual disability and CAMK2A variants, several of which were experimentally shown to be either loss-of-function or gain-of-function variants; three of these individuals also presented with autistic features.
Molecular Function
The product of this gene belongs to the serine/threonine protein kinases family, and to the Ca(2+)/calmodulin-dependent protein kinases subfamily. The alpha chain encoded by this gene is required for hippocampal long-term potentiation (LTP) and spatial learning. In addition to its calcium-calmodulin (CaM)-dependent activity, this protein can undergo autophosphorylation, resulting in CaM-independent activity.
External Links
References
Type
Title
Type of Disorder
Associated Disorders
Author, Year
Primary
The contribution of de novo coding mutations to autism spectrum disorder
Autism Genome Project (AGP) cohort consisting of 2730 trio families and 5 parent-child duos collected at 15 clinical sites across US, Canada, and Europe (overlapping German samples in the discovery cohort were excluded from the AGP cohort)
Mice with Camk2a-E183V mutation have reduced forebrain Camk2a levels, with lower abundance in the synaptic subcellular fractions. The Camk2a-E183V mice also exhibit hyperactivity, social interaction deficits, and increased repetitive behaviors.
References
Type
Title
Author, Year
Primary
A Novel Human CAMK2A Mutation Disrupts Dendritic Morphology and Synaptic Transmission, and Causes ASD-Related Behaviors.
Model Type:
Genetic
Model Genotype:
Homozygous
Mutation:
CRISPR/Cas9 mediated nucleotide replacement is conducted by using the gRNA complement to the DNA sequence of Camk2a exon 8 along with the donor sequence containing the subsituted last two bases of the E183 codon with TG, resulting in the Camk2a-E183V mutation.
Allele Type: Targeted (knockin)
Strain of Origin: Not specified
Genetic Background: C57BL6J/DBA2J
ES Cell Line: Mutant ES Cell Line: Not specified
Model Source: Not specified
Model Type:
Genetic
Model Genotype:
Heterozygous
Mutation:
CRISPR/Cas9 mediated nucleotide replacement is conducted by using the gRNA complement to the DNA sequence of Camk2a exon 8 along with the donor sequence containing the subsituted last two bases of the E183 codon with TG, resulting in the Camk2a-E183V mutation.
Allele Type: Targeted (knockin)
Strain of Origin: Not specified
Genetic Background: C57BL6J/DBA2J
ES Cell Line: Mutant ES Cell Line: Not specified
Model Source: Not specified
Description: Camk2a mutant mice exhibit no preference for the novel mouse over the empty cup unlike wildtype controls
Exp Paradigm: Three-chamber social approach test: social approach
Description: Increasaed percentage of camk2a is in the cytosolic fraction prepared from the mutant forebrains
Exp Paradigm: Fractionation; western blot: camk2a
Description: Total camk2a levels are reduced to about 50% with unchanged total camk2b levels in the mutant forebrains
Exp Paradigm: Western blot: camk2a
Description: Decreased percentage of camk2a is in the synaptosomal fraction prepared from the mutant forebrains
Exp Paradigm: Fractionation; western blot: camk2a
Description: Camk2a knockin hets exhibit no preference for the novel mouse over the familiar mouse unlike wildtype controls
Exp Paradigm: Three-chamber social approach test: social novelty