Not to be confused with 
CRISPR.
| CNTNAP1 | 
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| Identifiers | 
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| Aliases | CNTNAP1, CASPR, CNTNAP, NRXN4, P190, contactin associated protein 1, CHN3 | 
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| External IDs | OMIM: 602346; MGI: 1858201; HomoloGene: 2693; GeneCards: CNTNAP1; OMA:CNTNAP1 - orthologs | 
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| | Gene location (Mouse) | 
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 |  |  | Chr. | Chromosome 11 (mouse) | 
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 |  |  | Band | 11|11 D | Start | 101,061,349 bp | 
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 | End | 101,081,550 bp | 
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| | RNA expression pattern | 
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 | Bgee | | Human | Mouse (ortholog) | 
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 | | Top expressed in |  | right hemisphere of cerebellum
 Region I of hippocampus proper
 postcentral gyrus
 right frontal lobe
 Brodmann area 46
 superior frontal gyrus
 orbitofrontal cortex
 lateral nuclear group of thalamus
 prefrontal cortex
 Brodmann area 9
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 | | Top expressed in |  | superior frontal gyrus
 dentate gyrus of hippocampal formation granule cell
 primary visual cortex
 cerebellar cortex
 neural layer of retina
 zygote
 lumbar subsegment of spinal cord
 perirhinal cortex
 secondary oocyte
 entorhinal cortex
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 |  | More reference expression data | 
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 | BioGPS |  | 
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| Wikidata | 
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CASPR also known as Contactin associated protein 1, Paranodin and CASPR1 is a protein that in humans is encoded by the CNTNAP1 gene.
CASPR is a part of the neurexin family of proteins, hence its another name "Neurexin IV". CASPR is a membrane protein found in the neuronal membrane in the paranodal section of the axon[[]] in myelinated neurons, between the Nodes of Ranvier containing Na+ channels, and juxtaparanode, which contains K+ channels. During myelination, caspr associates with contactin in a cis complex, though its precise role in myelination is not yet understood.