Recent trio exome analysis identified predicted pathogenic variants in the gene CAMSAP3 in two patients with clinical features of generalized epilepsy. The study presented in the preprint pursued functional validation to determine whether these variants could plausibly contribute to disease. The authors frame this work in the context of accelerating gene discovery by next-generation sequencing and the recognized need to validate newly associated genes to establish causation and inform clinical care.
CAMSAP3 is known to regulate non-centrosomal microtubule dynamics and to influence the acetylation state of microtubules, processes that are important for normal axonal differentiation and neuronal migration. To test effects of the patient-associated variants, the investigators overexpressed the variant CAMSAP3 constructs in cultured HEK cells. Overexpression of the patient variants led to measurable protein degradation compared with control constructs, indicating impaired protein stability.
In the same cellular system, expression of the variant proteins produced dysregulation of microtubule acetylation, a post-translational modification associated with stable axonal microtubules and normal axon development. These cell-based findings provide mechanistic evidence that the patient variants disrupt CAMSAP3 function at the level of protein integrity and cytoskeletal regulation.
To extend the functional analysis in vivo, the authors generated a Camsap3 knockout zebrafish model. In these animals, axonal microtubule acetylation was increased, recapitulating the acetylation phenotype seen in cultured cells expressing patient variants. This concordance between cell and animal models supports a loss-of-function interpretation for the human variants.
The knockout zebrafish also exhibited abnormal development of inhibitory interneurons. The authors report aberrant inhibitory interneuron development as a notable cellular phenotype in the mutant fish, suggesting a developmental disruption of inhibitory circuitry that could predispose to network hyperexcitability. Details such as specific interneuron subtypes, developmental timing, or quantitative measures were not reported in the source beyond the general observation of abnormal inhibitory interneuron development.
Camsap3 knockout zebrafish displayed behavioral manifestations consistent with seizure activity, described as seizure-like swimming behaviors. These observable motor phenotypes indicate altered neural network function in the mutant animals.
Electrophysiologic assessment using local field potential recordings revealed epileptiform activity in the knockout fish. The combination of overt seizure-like behaviors and abnormal local field potentials provides phenotypic evidence that loss of Camsap3 function can produce seizure vulnerability in vivo.
Taken together, the human genetic findings, cellular assays, and the zebrafish knockout phenotype form a chain of evidence supporting a causative role for CAMSAP3 in generalized genetic epilepsy. The data link predicted pathogenic human variants to biochemical disruption (protein degradation and altered microtubule acetylation) and to organismal phenotypes consistent with epilepsy (interneuron development defects, seizure-like behavior, and epileptiform electrophysiology).
These results provide important functional validation for CAMSAP3 as an epilepsy-associated gene. The source emphasizes the value of integrating patient sequencing with cell-based and animal models to move from association toward causation. The preprint does not report additional clinical outcomes, therapeutic implications, or detailed quantitative measures for some phenotypes; those steps would require further study.
The authors declared no competing interests. Funding sources reported include the National Institute of Neurological Disorders and Stroke and additional institutional or foundation support listed by the authors. The work was posted as a preprint on bioRxiv; the source indicates the preprint was posted September 04, 2026. The copyright and license information provided in the source indicates the authors have granted bioRxiv a license to display the preprint under a CC-BY 4.0 International license.
Overall, the study integrates human genetics, cell biology, and an animal knockout model to support a loss-of-function mechanism for CAMSAP3 in generalized genetic epilepsy. Further clinical correlation and mechanistic dissection were not reported in the source and will be needed to translate these findings into diagnostic or therapeutic practice.