<div class="infobox infobox-gene">
| | |
|---|---|
| Gene Symbol | KANSL1 |
| Full Name | KAT8 Regulatory NSL Complex Subunit 1 |
| Aliases | KIAA1267, MSL1v1 |
| Chromosome | 17q21.31 |
| NCBI Gene ID | [284058](https://www.ncbi.nlm.nih.gov/gene/284058) |
| OMIM | [612452](https://omim.org/entry/612452) |
| Ensembl | [ENSG00000120071](https://ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000120071) |
| UniProt | [Q7Z3B3](https://www.uniprot.org/uniprot/Q7Z3B3) |
| Associated Diseases | Koolen-de Vries syndrome, [PSP](/diseases/progressive-supranuclear-palsy), [CBD](/diseases/corticobasal-degeneration), [FTD](/diseases/frontotemporal-dementia) |
</div>
<div class="infobox infobox-gene">
| | |
|---|---|
| Gene Symbol | KANSL1 |
| Full Name | KAT8 Regulatory NSL Complex Subunit 1 |
| Aliases | KIAA1267, MSL1v1 |
| Chromosome | 17q21.31 |
| NCBI Gene ID | [284058](https://www.ncbi.nlm.nih.gov/gene/284058) |
| OMIM | [612452](https://omim.org/entry/612452) |
| Ensembl | [ENSG00000120071](https://ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000120071) |
| UniProt | [Q7Z3B3](https://www.uniprot.org/uniprot/Q7Z3B3) |
| Associated Diseases | Koolen-de Vries syndrome, [PSP](/diseases/progressive-supranuclear-palsy), [CBD](/diseases/corticobasal-degeneration), [FTD](/diseases/frontotemporal-dementia) |
</div>
KANSL1 encodes a scaffold subunit of the non-specific lethal (NSL) complex, a histone acetyltransferase complex that catalyzes acetylation of histone H4 at lysine 16 (H4K16ac) through its catalytic partner KAT8. The NSL complex regulates chromatin accessibility and gene expression critical for neuronal development, synaptic plasticity, and neuronal survival. KANSL1 resides within the 17q21.31 locus, one of the strongest genetic risk factors for [progressive supranuclear palsy](/diseases/progressive-supranuclear-palsy) and [corticobasal degeneration](/diseases/corticobasal-degeneration), making it a gene of paramount importance in tauopathy research.
The KANSL1 gene spans approximately 168 kb on chromosome 17q21.31 and contains 16 exons encoding a 1,105-amino-acid protein. The 17q21.31 locus exists in two distinct haplotype forms — the directly oriented H1 haplotype and the inverted H2 haplotype — a ~900 kb inversion polymorphism present in approximately 20% of Europeans[@stefansson2005]. The H1 haplotype, and particularly the H1c sub-haplotype, is strongly associated with increased risk for PSP and CBD, while the H2 haplotype appears protective[@hglinger2011].
KANSL1 is ubiquitously expressed but shows particularly high expression in the brain, including the [cerebral cortex](/brain-regions/cerebral-cortex), [hippocampus](/brain-regions/hippocampus), and [basal ganglia](/brain-regions/basal-ganglia) — regions vulnerable in tauopathies.
KANSL1 functions as a structural scaffold within the NSL complex, directly interacting with KAT8 (MOF) and additional subunits including KANSL2, KANSL3, WDR5, PHF20, MCRS1, and OGT. The complex acetylates histone H4K16, a modification critical for chromatin decompaction and transcriptional activation[@cai2010]. KANSL1 bridges the catalytic KAT8 subunit to regulatory components, and its loss destabilizes the entire NSL complex.
H4K16 acetylation catalyzed by the NSL complex is one of the most abundant [histone modifications](/entities/histone-modifications) in euchromatin. It prevents higher-order chromatin fiber compaction by disrupting internucleosomal contacts, maintaining an open chromatin state permissive for transcription. In [neurons](/entities/neurons), this is essential for activity-dependent gene expression, synaptic plasticity genes, and neuroprotective transcriptional programs[@koolen2016].
Recent studies have revealed a direct role for KANSL1 in [autophagy](/mechanisms/autophagy-lysosomal-pathway) regulation independent of its chromatin function. KANSL1 facilitates the transcription of [autophagy](/entities/autophagy) genes by maintaining promoter accessibility, and its depletion leads to impaired autophagosome formation and lysosomal clearance[@li2019]. This is particularly relevant to tauopathies, where autophagy dysfunction contributes to [tau](/proteins/tau) accumulation.
KANSL1 participates in the DNA damage response by facilitating H4K16 acetylation at double-strand break sites, which promotes recruitment of repair factors. Neurons, being post-mitotic, rely heavily on efficient DNA repair for long-term survival, and KANSL1 deficiency may increase vulnerability to age-related DNA damage accumulation[@sharma2010].
Heterozygous loss-of-function mutations in KANSL1 cause Koolen-de Vries syndrome (KdVS; OMIM 610443), a neurodevelopmental disorder characterized by intellectual disability, hypotonia, speech delay, distinctive facial features, and behavioral abnormalities including friendly demeanor. KdVS demonstrates that KANSL1 haploinsufficiency profoundly disrupts neurodevelopment[@koolen2012].
The 17q21.31 H1 haplotype containing KANSL1 is the strongest genetic risk factor for [PSP](/diseases/progressive-supranuclear-palsy) (OR ~5.5) and a significant risk factor for [CBD](/diseases/corticobasal-degeneration) and [FTD](/diseases/frontotemporal-dementia)[@hglinger2011]. While the [MAPT](/genes/mapt) gene encoding [tau](/proteins/tau) also resides within this locus, functional genomic studies suggest that altered KANSL1 expression contributes independently to disease risk through reduced H4K16 acetylation in vulnerable brain regions, impaired autophagy and accumulation of misfolded 4R-tau species, epigenetic changes that shift neuronal transcriptomes toward vulnerability states, and DNA repair deficiency increasing susceptibility to age-related genotoxic stress.
The H1c sub-haplotype is associated with increased [MAPT](/proteins/tau) expression and potentially altered KANSL1 splicing, creating a compounded risk effect[@allen2014].
While the 17q21.31 association is strongest for 4R-tauopathies, some studies suggest modest effects on [Alzheimer's disease](/diseases/alzheimers-disease) risk, possibly mediated through tau pathology contributions[@myers2007].
KANSL1 is broadly expressed in the adult brain with highest levels in the [cortex](/brain-regions/cerebral-cortex) (particularly frontal and temporal lobes), [hippocampus](/brain-regions/hippocampus) (CA1 and dentate gyrus), [basal ganglia](/brain-regions/basal-ganglia) (striatum and globus pallidus), and [cerebellum](/brain-regions/cerebellum) (Purkinje cells).
Allen Human Brain Atlas: [KANSL1 expression](https://human.brain-map.org/microarray/search/show?search_term=KANSL1)
KANSL1-related pathways offer several therapeutic angles for tauopathies: [HDAC](/entities/hdac-enzymes) inhibitors that mimic H4K16 acetylation effects, autophagy enhancers that compensate for reduced KANSL1-dependent autophagic flux, epigenetic therapies targeting the specific chromatin changes at the 17q21.31 locus, and gene therapy approaches for KdVS patients.
The following diagram shows the key molecular relationships involving KANSL1 — KAT8 Regulatory NSL Complex Subunit 1 discovered through SciDEX knowledge graph analysis: