A total of three de novo loss-of-function (LoF) variants in the ANK2 gene have been identified in ASD probands from the Simons Simplex Collection (PMIDs 22542183, 24267886, 25363768), while a fourth de novo LoF in this gene was identified in an ASD proband from the Autism Sequencing Consortium in De Rubeis et al., 2014 (PMID 25363760). Analysis of rare coding variation in 3,871 ASD cases and 9,937 ancestry-matched or paternal controls from the Autism Sequencing Consortium (ASC) in De Rubeis et al., 2014 identified ANK2 as a gene meeting high statistical significance with a FDR 0.01, meaning that this gene had a 99% chance of being a true autism gene (PMID 25363760). This gene was identified in Iossifov et al. 2015 as a strong candidate to be an ASD risk gene based on a combination of de novo mutational evidence and the absence or very low frequency of mutations in controls (PMID 26401017). A two-stage analysis of rare de novo and inherited coding variants in 42,607 ASD cases, including 35,130 new cases from the SPARK cohort, in Zhou et al., 2022 identified ANK2 as a gene reaching exome-wide significance (P < 2.5E-06).
Molecular Function
This gene encodes a member of the ankyrin family of proteins that link the integral membrane proteins to the underlying spectrin-actin cytoskeleton. This gene is associated with Long QT syndrome 4 (LQT4) [MIM:600919], a heart disorder characterized by a prolonged QT interval on the ECG and polymorphic ventricular arrhythmias.
External Links
References
Type
Title
Type of Disorder
Associated Disorders
Author, Year
Primary
De novo gene disruptions in children on the autistic spectrum.
Model Type:
Genetic
Model Genotype:
Homozygous
Mutation:
Homozygous ABe22*/* mice, models for human R895* [c.2683C > T], R990* [c.2968C > T] de novo nonsense mutations associated with ASD, have a stop codon inserted into exon 22 producing nonsense-mediated decay in both the 220-kDa and giant ankB polypeptides.
Allele Type: Partial knockout
Strain of Origin: 129SVJ
Genetic Background: C57Bl/6
ES Cell Line: Mutant ES Cell Line: Model Source:
Model Type:
Genetic
Model Genotype:
Heterozygous
Mutation:
Heterozygous ABe22*/+ mice, models for human R895* [c.2683C > T], R990* [c.2968C > T] de novo nonsense mutations associated with ASD, have a stop codon inserted into exon 22 producing nonsense-mediated decay and a 50% reduction in both the 220-kDa and giant ankB polypeptides.
Allele Type: Partial knockout
Strain of Origin: 129SVJ
Genetic Background: C57Bl/6
ES Cell Line: Mutant ES Cell Line: Model Source:
Model Type:
Genetic
Model Genotype:
Heterozygous
Mutation:
A knockin ABe37fs/ was generated using CRISPR to introduce a P2580fs mutation in C57BL/6J mice, similar to the R2608fs human ANK2 de novo frameshift mutation in exon 37 of ANK2 associated with ASD. To minimize the likelihood of off-target excisions from a guide RNA (gRNA) targeting the precise human mutation site since the DNA sequence corresponding to R2608 has similarity with other sites in the mouse genome, P2580, 28 residues away from the actual human site was targeted, since the gRNA for this site had higher genomic selectivity. The frameshift mutation at P2580 was confirmed by DNA seque
Allele Type: Mimic ASD LOF Knockin
Strain of Origin: Genetic Background: C57BL/6J
ES Cell Line: Mutant ES Cell Line: Model Source: C. Guo (Janelia Gene Targeting and Transgenics Resource)
Model Type:
Genetic
Model Genotype:
Homozygous
Mutation:
A knockin mouse ABe37fs/fs was generated using CRISPR to introduce a P2580fs mutation in C57BL/6J mice, similar to the R2608fs human ANK2 de novo frameshift mutation in exon 37 of ANK2 associated with ASD. To minimize the likelihood of off-target excisions from a guide RNA (gRNA) targeting the precise human mutation site since the DNA sequence corresponding to R2608 has similarity with other sites in the mouse genome, P2580, 28 residues away from the actual human site was targeted, since the gRNA for this site had higher genomic selectivity. The frameshift mutation at P2580 was confirmed by DN
Allele Type: Mimic ASD LOF Knockin
Strain of Origin: C57BL/6J
Genetic Background: C57BL/6J
ES Cell Line: Mutant ES Cell Line: Model Source: C. Guo (Janelia Gene Targeting and Transgenics Resource)
Model Type:
Genetic
Model Genotype:
Homozygous
Mutation:
Ank2 conditional knock-out mouse, ABe37f/f; Nestin-Cre mice, where exon 37 of the Ank2 gene was deleted under the control of Nestin-Cre-recombinase, where giant ankB is lost in approximately 90% of neural and glial progenitors.
Allele Type: Conditional (knockout)
Strain of Origin: Genetic Background: C57BL/6J
ES Cell Line: Mutant ES Cell Line: 129S6/SvEvTac-derived TL1 ES cells
Model Source: Duke Transgenic Core
Model Type:
Genetic
Model Genotype:
Heterozygous
Mutation:
C57BL/6J-background transgenic mice harboring a cassette composed of exon 4 of Ank2 floxed by loxP, along with neomycin-resistance and EGFP genes flanked by Flp-Frt (Ank2fl/fl mice), were generated by Biocytogen. To generate floxed heterozygous mice (Ank2fl/+), the cassette was removed by crossing Ank2fl/fl mice with protamine-Flp mice (C57BL/6J). To generate Ank2 global knockout (KO) mice, fertilized eggs were treated at the two-cell embryo stage with purified HTNC, a cell-permeable Cre recombinase (histidine-TAT-nuclear localization-Cre fusion peptide).
Allele Type: Knockout
Strain of Origin: Not specified
Genetic Background: C57BL/6J
ES Cell Line: Not specified
Mutant ES Cell Line: Model Source: Biocytogen
Model Type:
Genetic
Model Genotype:
Homozygous
Mutation:
To generate Ank2 conditional knockout (cKO) mice, Ank2fl/+ male mice were crossed with Emx1-Cre female mice (MGI:2684610) to avoid germline transmission of Emx1-Cre. From this mating, Emx1-Cre;Ank2fl/+ female mice were maintained. Ank2fl/+ mice were crossed with each other to produce Ank2fl/fl male mice. Emx1-Cre;Ank2fl/+ female mice were crossed with Ank2fl/fl male mice to produce Ank2fl/fl mice (wildtype controls) and Emx1-Cre;Ank2fl/fl (Ank2-cKO) mice.
Allele Type: Conditional knockout
Strain of Origin: Not specified
Genetic Background: C57BL/6J
ES Cell Line: Not specified
Mutant ES Cell Line: Model Source: Biocytogen; Jackson
Model Type:
Genetic
Model Genotype:
Heterozygous
Mutation:
Ankyrin-B (Ank2) floxed mice with loxP sites flanking exon 24 (MGI:5708349, Peter Mohler) were crossed with Emx1-Cre mice (MGI:2684610), which highly express Cre recombinase at embryonic day 10.5, to generate prenatal deletion of the gene.
Allele Type: Conditional knockout
Strain of Origin: 129/Sv
Genetic Background: B6.129(Cg)*B6.129S2
ES Cell Line: Not specified
Mutant ES Cell Line: Model Source: Dr. Peter Mohler; Jackson
Model Type:
Genetic
Model Genotype:
Homozygous
Mutation:
Ankyrin-B (Ank2) floxed mice with loxP sites flanking exon 24 (MGI:5708349, Peter Mohler) were crossed with NEX-Cre mice (MGI:2668659), which express Cre recombinase in excitatory neurons in the neocortex and hippocampus, but not inhibitory neurons, during embryonic development.
Allele Type: Conditional knockout
Strain of Origin: 129/Sv
Genetic Background: B6.129(Cg)
ES Cell Line: Not specified
Mutant ES Cell Line: Model Source: Dr. Peter Mohler; Goebbels et al. 2006 (PMID 17146780)
Model Type:
Genetic
Model Genotype:
Heterozygous
Mutation:
Ankyrin-B (Ank2) floxed mice with loxP sites flanking exon 24 (MGI:5708349, Peter Mohler) were crossed with NEX-Cre mice (MGI:2668659), which express Cre recombinase in excitatory neurons in the neocortex and hippocampus, but not inhibitory neurons, during embryonic development.
Allele Type: Conditional knockout
Strain of Origin: 129/Sv
Genetic Background: B6.129(Cg)
ES Cell Line: Not specified
Mutant ES Cell Line: Model Source: Dr. Peter Mohler; Goebbels et al. 2006 (PMID 17146780)
Model Type:
Genetic
Model Genotype:
Homozygous
Mutation:
Ankyrin-B (Ank2) floxed mice with loxP sites flanking exon 24 (MGI:5708349, Peter Mohler) were crossed with CamK2a-Cre mice (MGI:2177650), which fully express Cre recombinase in the cortex after 4 weeks of age, to generate postnatal deletion of the gene.
Allele Type: Conditional knockout
Strain of Origin: 129/Sv
Genetic Background: B6.129(Cg)*B6.Cg
ES Cell Line: Not specified
Mutant ES Cell Line: Model Source: Dr. Peter Mohler; Jackson
Model Type:
Genetic
Model Genotype:
Homozygous
Mutation:
Ankyrin-B (Ank2) floxed mice with loxP sites flanking exon 24 (MGI:5708349, Peter Mohler) were crossed with Emx1-Cre mice (MGI:2684610), which highly express Cre recombinase at embryonic day 10.5, to generate prenatal deletion of the gene.
Allele Type: Conditional knockout
Strain of Origin: 129/Sv
Genetic Background: B6.129(Cg)*B6.129S2
ES Cell Line: Not specified
Mutant ES Cell Line: Model Source: Dr. Peter Mohler; Jackson
Description: 2 wk old ank2 null mice that survived were much smaller and showed reduced locomotion owing to size ( data not shown in article)
Exp Paradigm: NA
Description: Ank2 null mice are born in a normal mendelian ratio but 95% of them die early after birth, within pnd 8. all die within first 21 days
Exp Paradigm: NA
Description: There is increase in axon fasciculation in ank2 null mice. many axons have increased diameter and contain multivescicular bodies.
Exp Paradigm: NA
Description: Mutant cortices show increase in interhemispheric asymmetry of long tracks. mutants show small differences in asymmetry in the whole brain that are not statistically significant.
Exp Paradigm: Interhemispheric track asymmetry was assayed for either the entire brain or for the cerebral cortex by performing voxel-based comparisons within hemispheres of individual mice
Description: Mutants show unmyelinated axon shafts in the corpus callosum with microtubules arranged in a broad, low amplitude peak shifted 40 to 50nm from the cell membrane whereas control axons show a cortical microtubule population centered around 20 to 30 nm from the plasma membrane. mutants show no change in the number of microtubules in the axons.
Exp Paradigm: Corpus callosum
Dti: fractional anisotropy or relative anisotropy in brain regions1
Increased
Description: Mutants show small but significant increases in connectivity using fractional anisotropy.
Exp Paradigm: Whole brain; whole brain pair-wise connectivity of white matter tracks was measured using fractional anisotropy in an atlas of 332 brain regions from the dti images
Description: Mutants show no expression of 440kda ankb but express a truncated 290kda ankb at half the level of 440kda ankb and normal levels of 220kda ankb.
Exp Paradigm: NA
Description: Mutants show lower intensity of signal for in situ proximity of l1cam and 220kda ankb or 440kda ankb along the axon tracts of the corpus callosum. mutants show lower intensity of signal for in situ proximity of l1cam and 290kda truncated ankb along the axon tracts of the corpus callosum.
Exp Paradigm: Corpus callosum
Description: Mutants show lower intensity of signal for in situ proximity of l1cam and 220kda ankb or 440kda ankb along the axon tracts of the corpus callosum. mutants show lower intensity of signal for in situ proximity of l1cam and 290kda truncated ankb along the axon tracts of the corpus callosum.
Exp Paradigm: NA
Description: Heterozygous mutants show decrease of both long and short variants of Ankyrin-B in total lysate from whole brain, with about 40-50% protein levels for the short variant, and 50-60% levels of the long variant, compared to wildtype.
Description: Conditional knockouts show increased ambulatory activity, measured by total distance moved in a novel home cage environment.
Exp Paradigm: Novel home cage, behavior measured for 10 minutes after a 10-minute habituation.
Description: Conditional knockouts show increased mean firing rate in the somatosensory cortex, layer 2/3 and layer 5, as well as increased mean burst rate in later 2/3. There is also a trend for increased local field potential frequency in layer 2/3.
Exp Paradigm: Multielectrode array
Description: Conditional knockouts show decreased self grooming in a novel home cage environment.
Exp Paradigm: Novel home cage, behavior measured for 10 minutes after a 10-minute habituation.
Description: Conditional knockouts show decreased digging behavior in a novel home cage environment.
Exp Paradigm: Novel home cage, behavior measured for 10 minutes after a 10-minute habituation.
Description: Conditional knockouts show increased chemically induced seizures, with reduced latency to seizure, greater percentage of animals showing seizures, and higher frequency and duration of stage 2 seizures.
Description: Conditional knockouts show decreased social memory, measured by a lack of preference for a novel social stimulus over a familiar social stimulus.
Description: Conditional knockouts show decreased anxiety behavior, measured by increased time spent and increased number of entries to light chamber in light-dark exploration test.
Description: Conditional knockouts show decreased anxiety behavior, measured by increased time spent and number of entries into open arms of the elevated plus maze test.
Description: Conditional knockouts show decreased expression of both long and short variants of Ankyrin-B in total lysates and, in synaptosomal fractions from cortex and hippocampus, with 10% of wildtype levels for the short variant and 20% of wildtype levels for the long variant.
Exp Paradigm: Fractionation
Description: Conditional knockouts show decreased levels of voltage-gated potassium channels Kv7.2 and Kv7.3 in total lysates and synaptosomal fraction of cortex and hippocampus. Conditional knockouts also show decreased levels of voltage-gated sodium channels Nav1.2 and Nav1.6 in total lysates from cortex and hippocampus, but not significantly decreased levels in synaptosomal fraction.
Exp Paradigm: Kv7.2, Kv7.3, NaV1.2, NaV1.6
Description: Conditional knockouts show proteins with downregulated and proteins with upregulated post-translational modifications. Specifically, potassium voltage-gated channels show downregulation of post-translational modifications.
Description: NEX-driven knockout mice, with prenatal deletion of Ank2 in excitatory neurons, exhibit spontaneous seizures, which lead to an early lethality, similar to Emx-driven knockout mice.
Description: Acute brain slices from the conditional knockouts with prenatal deletion of Ank2 show decreased calcium event half-width in layers 2/3 somatosensory cortex.
Description: Acute brain slices from the conditional knockouts with prenatal deletion of Ank2 show increased calcium event frequency in layers 2/3 somatosensory cortex.
Description: Acute brain slices from the conditional knockouts with prenatal deletion of Ank2 show increased calcium event amplitude in layers 2/3 somatosensory cortex.
Description: Conditional knockouts with prenatal deletion of Ank2 show spontaneous seizures, with a frequency of approximately 2 seizures per hour, and a duration of approximately 50 seconds per seizure, starting at age P20.
Description: Emx-driven knockout mice, with prenatal deletion of Ank2, exhibit spontaneous seizures starting at about P20. Spontaneous seizures in conditional knockout mice lead to 50% lethality at age P36 and 100% lethality at 9 months of age.
Description: Conditional knockouts with prenatal deletion of Ank2 show increased expression of Kalrn, and reduced expression of RPS4X in synaptosomal fraction.
Exp Paradigm: Kalrn, RPS4X
Description: Western blotting of cortical homogenates show Ankyrin-B protein levels are sharply reduced when Cre is expressed. Ankyrin-B levels are specifically reduced in the synaptosomal fraction as well.
