Table 2

- Patients with AHC phenotype

PatientSexAge of onsetPhenotypePresenting symptoms
AHCDystoniaCognition and BehaviorSeizuresOther
OnsetOffsetDuration    
1F3 yearsc.998T>A: p.Val333Asp de novo Pathogenic (PS2;PP3;PM1;PM2;PP5)3 years7 years controlled by carbamazepinelast for hours Impaired speech mild intellectual disabilitynone 
2F2 yearsc.2435A>T: p.D812Val de novo Pathogenic (PM1;PS2;PM5;PP3;PM2)2 years11 yearshours to days Global developmental delay + Autistic featuresAt 2 years, intractable, Atonic and Generalized Tonic/Clonic 
3M15 monthsc.1198G>A: p.Glu400Lys de novo Likely Pathogenic (PS2;PM2;PP5)15 months3 yearshours to days Global Developmental DelayAt 34 months Focal seizureNystagmus
4M3 yearsc.2284G>T: p.Gly762Cys de novo Pathogenic (PM2;PS2;PM5;PP3;PM5)3 years6 years15-30 mins Aggressive and hyperactiveAt 8 years Focal secondarily generalized. Controlled on Topamax. 
5F2 monthsc.2434G>A: p.D812N de novo Pathogenic (PM1;PS2;PS3;;PM5; PP3;PM5;PM2)2 months1-2 months triggered by emotional stress treated by flunarizine and currently by carbamazepinehours to daysMild dystoniaGlobal Developmental Delay, aggressive and hyperactiveAt 2 months Focal with secondarily generalizedSpasticity L>R
  • Mean=24 months age of onset, Group 1 participants 60% female and 40% male; mean age=24 months. AHC-alternating hemiplegia of childhood, L-left, R-right