KCTD7 gene

---

This gene encodes a member of the potassium channel tetramerization domain-containing protein family. Family members are identified on a structural basis and contain an amino-terminal domain similar to the T1 domain present in the voltage-gated potassium channel. Mutations in this gene have been associated with progressive myoclonic epilepsy-3. Alternative splicing results in multiple transcript variants.[provided by RefSeq, Jan 2011]

May be involved in the control of excitability of cortical neurons.

Epilepsy, progressive myoclonic 3

Defects in KCTD7 are a cause of opsoclonus-myoclonus ataxia-like syndrome. Opsoclonus myoclonus ataxia syndrome (OMS) is a rare pervasive and frequently permanent disorder that usually develops in previously healthy children with normal premorbid psychomotor development and characterized by association of abnormal eye movements (opsoclonus), severe dyskinesia (myoclonus), cerebellar ataxia, functional regression, and behavioral problems. The syndrome is considered to be an immune-mediated disorder and may be tumor-associated or idiopathic. OMS is one of a few steroid responsive disorders of childhood. KCTD7 mutations have been found in a patient with an atypical clinical presentation characterized by non-epileptic myoclonus and ataxia commencing in early infancy, abnormal opsoclonus-like eye movements, improvement of clinical symptoms under steroid treatment, and subsequent development of generalized epilepsy (PubMed:22638565).

Epilepsy, progressive myoclonic 3, with or without intracellular inclusions (EPM3): An autosomal recessive, severe, progressive myoclonic epilepsy with early onset. Multifocal myoclonic seizures begin between 16 and 24 months of age after normal initial development. Neurodegeneration and regression occur with seizure onset. Other features include mental retardation, dysarthria, truncal ataxia, and loss of fine finger movements. EEG shows slow dysrhythmia, multifocal and occasionally generalized epileptiform discharges. In some patients, ultrastructural findings on skin biopsies identify intracellular accumulation of autofluorescent lipopigment storage material, consistent with neuronal ceroid lipofuscinosis. [MIM:611726]

Cytogenetic Location: 7q11.21, which is the long (q) arm of chromosome 7 at position 11.21

Molecular Location: base pairs 66,628,881 to 66,643,229 on chromosome 7 (Homo sapiens Updated Annotation Release 109.20190905, GRCh38.p13) (NCBI)