Features include always present findings: Hand tremor and Dystonia; and common findings: Torticollis, Rotary nystagmus, Writer's cramp, and Impaired tandem gait and others. 13 total HPO annotations.

KCNN2 encodes potassium calcium-activated channel subfamily N member 2 (579 aa). Small conductance calcium-activated potassium channel that mediates the voltage-independent transmembrane transfer of potassium across the cell membrane through a constitutive interaction with calmodulin which binds the intracellular calcium allowing its opening. Highest expression in Adrenal Gland (24.6 TPM) and Pituitary (9.5 TPM).

Dystonia 34, myoclonic is associated with mutations in the KCNN2 gene on chromosome 5.

The KCNN2 protein participates in KCNN2 transports K+ from the cytosol to the extracellular region, CHRNA9:CHRNA10:AcCho transports Ca2+ from the extracellular region to the cytosol, and Acetylcholine inhibits contraction of outer hair cells pathways.

KCNN2 is classified as a druggable target (Cell Surface, Druggable Genome, and Ion Channel categories) with score 3.3.

Genetic testing for KCNN2 is available. Testing is considered confirmatory for diagnosis.

Phenotype severity distribution: 2 always present features, 7 common features.

No clinical trials have been registered for dystonia 34, myoclonic.

2 publications have been identified in PubMed for dystonia 34, myoclonic. Research spans Case Report / Case Series (100%).

Recent Publications

• Brooker SM (2025). [PMID: 40590478](https://pubmed.ncbi.nlm.nih.gov/40590478/). *Ann Neurol*. [Case Report / Case Series]

• Iwaizumi M (2025). [PMID: 39780213](https://pubmed.ncbi.nlm.nih.gov/39780213/). *Hered Cancer Clin Pract*. [Case Report / Case Series]