Association of early-onset epileptic encephalopathy with involuntary movements – Case series and literature review

GNAO1-related neurodevelopmental disorder: Literature review and caregiver survey

“…The search yielded 86 cases including 38 variants across 15 publications from 2013 to 2021 (Supplementary Table) [1] , [2] , [3] , [4] , [5] , [6] , [8] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] , [34] , [35] , [36] , [37] , [38] . Table 2 summarizes the clinical characteristics.…”

Epileptic dyskinetic encephalopathy in KBG syndrome: Expansion of the phenotype

“…We report a novel presentation of KBG syndrome of severe developmental epileptic-dyskinetic encephalopathy, characterised by early-onset relentless hyperkinetic movements, epileptic spasms and LGS. Although not an ILAE-recognised term, the term epileptic-dyskinetic encephalopathy is a recently applied umbrella description for a group of genetic disorders occurring in the first year of life [12] , usually presenting with intractable involuntary (hyperkinetic) movements (dyskinesia, chorea, athetosis, dystonia or tremor) and co-existing, often severe, drug-resistant epilepsy. Seizures can present with, or without, a co-existing defined early-onset DEE syndrome (e.g.…”

“…EIEE-BS, IESS) and the dyskinesia can be mild or more overt, and even ballistic in nature. There is often a high rate (up to 82 %) of genetic diagnosis [13] and more commonly associated genes identified for this presentation include for example ARX, STXBP1, GNAO1, FOXG1, SCN8A, GRIN2B, CDKL5, GABRA2, CYFIP2, EEF1A2, SCN8A, SCN2A, SCN1A, GRIN1, GRIN2A, PIGP, HECW2, TBL1XR1, ALG13, SETD5 [12] , [13] , [14] . ANKRD11 , although not previously associated with this phenotype, should now be added to this list of causative genes linked with epileptic-dyskinetic encephalopathy, particularly when seeking to correlate variant identification to clinical presentation, as the dysmorphic and other clinical features of KGB syndrome are not usually present until later childhood.…”

STXBP1-Related Disorders: Clinical Presentation, Molecular Function, Treatment, and Future Directions

“…This had previously been described as ataxia-tremor-retardation syndrome without epilepsy [17,24]. A variety of other movement disorders have been identified as well, including hypomimia, bradykinesia, dystonia, dyskinesia, and choreoathetosis [21,22,24,32,33].…”