Table 2

(part iv) Table summarising findings for each child individually

Child (family)17181920
Necessary criteria
 Infantile hypotoniaYNNY
 Profound psychomotor retardationYYYY
 Convulsive disorders presenting with myoclonias and infantile spasmsYYYY
 Absence or early loss of visual fixationYYY?
 Atrophy of optic disc by 2 yearsYYYN
 Progressive brain atrophy: affecting cerebellum±brainstemY?YN
Supportive criteria
 Dysmorphic featuresYYYN
 Oedema of the face and limbsYYYY
Features contrary to PEHO
 Other featuresMicrocephaly at birthHypertonia in infancyHypertonia in infancy
Abnormal gyral formation
Diagnosis assigned
 Diagnosis assignedPEHO-likePEHO-likePEHO-likeExcluded
 Gene SCN1A No clear pathogenic mutation found PLAA
 InheritanceHeterozygous ADHomozygous AD
 Nucleotide changec.1252A>Cc.68G>T
 Protein changep.(Iso418Leu)p.(Gly23Val)
 ExAC frequency00
 Pathogenicity*SIFT=0.01SIFT=0.01 and see ref 26
  • Children 1–5 are from family A; children 8–10 are from family B; children 14–16 are from family C.

  • *For each mutation pathogenicity, details are within the paper. Here we give either a reference confirming pathogenicity or where this is unavailable, the SIFT score ().

  • ExAc, Exome Aggregation Consortium; PEHO, progressive encephalopathy, hypsarrhythmia and optic atrophy; SIFT, Scale Invariant Feature Transform.