Table 1

Clinical characteristics of the subjects with ADARB1 variants

Family 1 (Iraq)Family 2 (Egypt)Tan et al 10 (Caucasian, Hispanic, Azari)
Pt 1 (IV-7)Pt 2 (III-1)Pt 3 (III-2)4 pts, 4 families
Age at last FU, sex5.6 y, F6 y, F4.9 y, FMean 5.2 y, 4 M
Alive++++ (3), one died at 2 y
Consanguinity++++ (2)
Previous miscarriages++ (1)
Similarly affected siblings+ (2, deceased)+ (III-2)+ (III-1)
PregnancyRegular (38 we)Regular (40 we)Regular (38 we)Regular (3), pre-eclampsia (1)
Birth complications
OFC at birthN/A33.3 cm (−0.72 SD)33 cm (−0.7 SD)0.38 to −2.2 SD (2 N/A)
Neonatal course
Excessive crying+++N/A
Developmental history
Visual trackingPoor– (3)
Head control– (3)
Sit with support– (3)
Standing with support– (3)
Walking with support– (4)
Speech– (3), few words (1)
Intellectual disabilityProfoundProfoundProfoundProfound (2), severe (2)
Feeding difficulties++++ (4)
Dysmorphic features++++ (2)
OFC at last FU45 cm (−4.3 SD)43 cm (−5.8 SD)43 cm (−5.1 SD)−3.3 to −4.4 SD (mean −3.8 SD)
Neurological features
Axial hypotonia++++ (4)
Spastic tetraplegia++++ (2)
Hyperreflexia++++ (1)
Sleep disturbance++ (1)
OtherBruxism, insomniaTremor (1), staring spells (1), repetitive movements (1)
Strabismus++++ (1)
OtherCortical blindnessCortical blindnessCortical blindness (3)
ABRsN/ANormalNormalNormal (4)
Onset15 d4 mo5 mo2–7 mo (mean 4.3)
Frequency, durationDaily, 0.5–2 minDaily, 1–3 minDaily, 1–3 minWeekly to daily
Associated signsApnoea, staringHead deviation, vomitingHead deviationEye deviation, twitching, apnoea
EEGMFDs, slow backgroundMFDsBilateral TPDsMFDs, slow background
Status epilepticus+ (2)
Response to AEDs*– (4)
Current statusIntractableIntractableIntractableIntractable
Neuroimaging features†
Diffuse cerebral atrophy++++ (3), temporal lobes (1)
White matter loss++++ (2)
Delayed myelination+++ (2)
CCH++++ (3)
Enlarged ventricles++++ (3)
Basal ganglia T2-weighted hyperintensity+- (3)
Other featuresContractures, muscle wasting, 2 hypopigmented spots on the sternumPDALaryngomalacia (1), plagiocephaly (2), cryptorchidism (1), contractures and muscle wasting (1)
Metabolic investigations‡NormalNormalNormalNormal (4)
  • *AEDs included clonazepam, levetiracetam, phenytoin, topiramate, valproate and vigabatrin.

  • †MRI pictures of three out of four patients were available for review.

  • ‡Extended metabolic screening including organic acid in urine, acylcarnitine profile, ammonia and lactate.

  • ABRs, auditory brain responses; AEDs, antiepileptic drugs; CCH, corpus callosum hypoplasia; d, days; EEG, electroencephalogram; F, female; FS, focal seizures; FU, follow-up; GS, generalised seizures; GTCS, generalised tonic-clonic seizures; IS, infantile spasms; LGS, Lennox-Gastaut syndrome; M, male; MCS, myoclonic seizures; MFDs, multifocal discharges; mo, months; N/A, not available; OFCS, occipitofrontal circumference; PDA, patent ductus arteriosus; Pts, patients; s, syndrome; TPDs, temporoparietal discharges; TS, tonic seizures; we, weeks; y, years.