Myoclonic epilepsy of infancy
Synonyms: Benign myoclonic epilepsy of infancy · Benign myoclonus epilepsy of infancy · MEI
- Type
- Disease
- Group
- Disorder
- Inheritance
- Autosomal recessive
- Age of onset
- Infancy
- Status
- active
A rare infantile epilepsy syndrome characterized by an infantile-onset of sudden, frequent and generalized myoclonic seizures that occur in neurologically and developmentally normal patients, and later resolve during childhood with a generally favorable outcome.
Names in Orphadata languages
12 of 12 languages| Lang | Name | Synonyms |
|---|---|---|
| en | Myoclonic epilepsy of infancy | Benign myoclonic epilepsy of infancy · Benign myoclonus epilepsy of infancy · MEI |
| fr | Epilepsie myoclonique de l'enfance | Epilepsie myoclonique bénigne de l'enfance |
| de | Myoklonusepilepsie des Kindesalters | Benigne myoklonische Epilepsie des Kindesalters · MEI |
| es | Epilepsia mioclónica del lactante | Epilepsia mioclónica benigna del lactante |
| it | Epilessia mioclonica dell'infanzia | Epilessia mioclonica benigna dell'infanzia |
| nl | Myoclonusepilepsie in de kinderjaren | Goedaardige myoclonische epilepsie in de kinderjaren · Goedaardige myoclonusepilepsie in de kinderjaren · MEI |
| pt | Epilepsia mioclónica da infância | Epilepsia mioclónica benigna da infância |
| pl | Dziecięca padaczka miokloniczna | Dziecięca łagodna padaczka miokloniczna |
| cs | Myoklonická epilepsie u kojenců | Benigní myoklonická epilepsie kojenců |
| uk | Міоклонічна епілепсія раннього дитячого віку | Доброякісна міоклонічна епілепсія дитячого віку · Доброякісна міоклонусна епілепсія дитячого віку |
| zh | 婴儿肌阵挛癫痫 | 婴儿良性肌阵挛型癫痫 |
| tr | Süt çocuğu miyoklonik epilepsisi | Bebeklik döneminde selim miyoklonik epilepsi · Bebeklik döneminde selim miyoklonus epilepsisi |
Definition in:
Cross-references
qualifier = Orphanet mapping relation| Source | Code | Qualifier | ICD relation | Validation |
|---|---|---|---|---|
| OMIM | 605021 | NTBT | validated | |
| OMIM | 617976 | BTNT | validated | |
| OMIM | 618364 | BTNT | validated | |
| ICD-10 | G40.3 | NTBT | attributed | validated |
| ICD-11 | 8A61.1Y | NTBT | index | validated |
| MONDO | 0019486 | E | validated | |
| MONDO | 100566 | E | validated | |
| MONDO | 19486 | E | validated | |
| UMLS | C0751120 | E | validated |
E exact · NTBT this ORPHAcode is narrower than the target · BTNT broader than the target · ND not decided.
Classification
Preferential parent (Orphanet linearisation):
Parents in the classifications (1):
- ORPHA:693802Neonatal/infantile-onset epilepsy syndrome
rare genetic diseases; rare neurological diseases
No children.
Codes that Orphanet moved or referred to this one:
- ORPHA:352582Familial infantile myoclonic epilepsy moved to · inactive
Genes
3 direct| Gene | Association | Status | HGNC | Ensembl | OMIM | Locus | Name | Source of validation |
|---|---|---|---|---|---|---|---|---|
| TBC1D24 | Disease-causing germline mutation(s) (loss of function) in | Assessed | HGNC:29203 | ENSG00000162065 | 613577 | 16p13.3 | TBC1 domain family member 24 | 20727515[PMID] |
| CPLX1 | Disease-causing germline mutation(s) in | Assessed | HGNC:2309 | ENSG00000168993 | 605032 | 4p16.3 | complexin 1 | 28422131[PMID] |
| SCN8A | Disease-causing germline mutation(s) in | Assessed | HGNC:10596 | ENSG00000196876 | 600702 | 12q13.13 | sodium voltage-gated channel alpha subunit 8 | 29726066[PMID] |
Prevalence and incidence
2 records| Type | Class | Value | Area | Qualification | Validation | Source |
|---|---|---|---|---|---|---|
| Cases/families | 106 cases | Worldwide | Case(s) | Validated | ORPHANET | |
| Point prevalence | <1 / 1 000 000 | — | Worldwide | Class only | Validated | ORPHANET |
Value is Orphadata's ValMoy: the mean estimate per 100 000 for prevalence and incidence, the number of cases or families for case reports.
HPO phenotypes
34 annotations · validated 2026-02-23| HPO | Term (as annotated by Orphanet) | Diagnostic |
|---|---|---|
| Very frequent (99-80%) | ||
| HP:0007018 | Attention deficit hyperactivity disorder | |
| HP:0002069 | Bilateral tonic-clonic seizure | |
| HP:0001326 | EEG with irregular generalized spike and wave complexes | |
| HP:0002123 | Generalized myoclonic seizure | |
| HP:0001256 | Intellectual disability, mild | |
| HP:0001250 | Seizure | |
| Frequent (79-30%) | ||
| HP:0000718 | Aggressive behavior | |
| HP:0025190 | Bilateral tonic-clonic seizure with generalized onset | |
| HP:0001272 | Cerebellar atrophy | |
| HP:0002376 | Developmental regression | |
| HP:0011197 | EEG with focal spike waves | |
| HP:0007359 | Focal-onset seizure | |
| HP:0025373 | Interictal EEG abnormality | |
| HP:0000737 | Irritability | |
| HP:0001268 | Mental deterioration | |
| HP:0001336 | Myoclonus | |
| HP:0007057 | Poor hand-eye coordination | |
| HP:0002275 | Poor motor coordination | |
| HP:0011171 | Simple febrile seizure | |
| HP:0006891 | Thick cerebral cortex | |
| Occasional (29-5%) | ||
| HP:0001251 | Ataxia | |
| HP:0000643 | Blepharospasm | |
| HP:0010862 | Delayed fine motor development | |
| HP:0000750 | Delayed speech and language development | |
| HP:0001260 | Dysarthria | |
| HP:0002373 | Febrile seizure (within the age range of 3 months to 6 years) | |
| HP:0002121 | Generalized non-motor (absence) seizure | |
| HP:0001263 | Global developmental delay | |
| HP:0001249 | Intellectual disability | |
| HP:0002463 | Language impairment | |
| HP:0001112 | Leber optic atrophy | |
| HP:0007207 | Photosensitive tonic-clonic seizures | |
| HP:0000520 | Proptosis | |
| Very rare (<4-1%) | ||
| HP:0002301 | Hemiplegia | |
Run the differential on the 6 obligate / very frequent terms
Annotation source: 20797691[PMID]_23517570[PMID]_25719194[PMID]_10741954[PMID]_24469935[PMID]_18639309[PMID]_25564312[PMID]_27039230[PMID]_24691296[PMID]_15508932[PMID]_18639309[PMID]_22342656[PMID]_25894286[PMID]_22819072[PMID]_23889608[PMID]
Sources for this card
- Orphanet page: orpha.net/en/disease/detail/86909
- This record as JSON: /data/d/86909.json