Myoclonus, familial, 2: genes and variants
Myoclonus, familial, 2 is linked to 1 analyzed protein (SCN8A). 3 DNA variants are known to cause it; 12 more are uncertain, and 0 of those already look disease-causing on computable evidence.
Last updated 2026-09-30. Research information, not medical advice.
Genes linked to Myoclonus, familial, 2
SCN8A: Sodium channel protein type 8 subunit alpha
The protein forms Nav1.6, a voltage-gated sodium channel that sets the threshold and propagation of neuronal action potentials. It is widely important for neuronal excitability, and SCN8A variants are associated with developmental and epileptic encephalopathies.
3 disease-causing and 12 uncertain variants in SCN8A are linked to Myoclonus, familial, 2.
Known disease-causing variants in Myoclonus, familial, 2
| Variant | Position | Protein part | Clinical label |
|---|---|---|---|
| SCN8A S979N | 979 | II | Disease-causing (★) |
| SCN8A M1481K | 1481 | III | Disease-causing (★) |
| SCN8A P1719R | 1719 | IV | Disease-causing |
Same protein, different disease
- Early-infantile DEE is also caused by SCN8A variants; they fall mostly in different places as the Myoclonus, familial, 2 variants (90 disease-causing).
- Cognitive impairment with or without cerebellar ataxia is also caused by SCN8A variants; they fall mostly in different places as the Myoclonus, familial, 2 variants (22 disease-causing).
- Seizures, benign familial infantile, 3 is also caused by SCN8A variants; they fall mostly in different places as the Myoclonus, familial, 2 variants (12 disease-causing).
- Complex neurodevelopmental disorder is also caused by SCN8A variants; they fall mostly in different places as the Myoclonus, familial, 2 variants (8 disease-causing).
- Autosomal recessive inheritance is also caused by SCN8A variants; they fall mostly in different places as the Myoclonus, familial, 2 variants (3 disease-causing).
Diseases related to Myoclonus, familial, 2
- Early-infantile DEE, also linked to SCN8A
- Seizures, benign familial infantile, 3, also linked to SCN8A
- Amyotrophic lateral sclerosis, also linked to SCN8A
- Cardiac arrhythmia, also linked to SCN8A
- Complex neurodevelopmental disorder, also linked to SCN8A
- Cognitive impairment with or without cerebellar ataxia, also linked to SCN8A
- Epilepsy, also linked to SCN8A
- Fetal akinesia deformation sequence, also linked to SCN8A
- Infantile spasms, also linked to SCN8A
- Genetic developmental and epileptic encephalopathy, also linked to SCN8A
- Cerebellar ataxia, also linked to SCN8A
- Arthrogryposis multiplex congenita, also linked to SCN8A
Frequently asked questions
Which genes are linked to Myoclonus, familial, 2?
In CATVariant, Myoclonus, familial, 2 is linked to 1 analyzed protein: SCN8A (Sodium channel protein type 8 subunit alpha).
How many genetic variants are linked to Myoclonus, familial, 2?
16 variants: 3 are classified as disease-causing (pathogenic or likely pathogenic) in ClinVar and 12 are of uncertain significance or have conflicting reports.
Which uncertain variants in Myoclonus, familial, 2 look disease-causing?
None of the uncertain variants currently reaches the likely-pathogenic range on computable evidence alone.
About this data
Variant–disease links come from ClinVar, Open Targets and UniProt, pooled from the latest public CATVariant analysis of each human protein. Evidence scores use the ACMG/AMP Bayesian points scale with computable criteria only (position among known disease variants, rarity in gnomAD, calibrated predictors, deep mutational scanning); there is no family or patient data, so they prioritise variants for expert review and never classify them.
Download every variant as CSV · Browse all diseases · Methods · About the Center