Table 1

The clinical and molecular data of our cases and additional selected reported CLN8 cases with LI-NCL

CasesPatient AOur patients
Patient B
Patient CGao et al8 2018Allen et al9 2012Reinhardt et al. 2009 patient 3 & 410Beesley et al1 2016 child B
Country of originSaudi ArabiaSaudi ArabiaSaudi ArabiaChinaIrelandTurkeyUK
ConsanguinityYesYesYesNoNoYesNo
Abortion historyYesYesYesNot reportedNot reportedNot reportedNot reported
Onset of disease2 years2 years3 years4 years4 years2.5 years4 years
Age at diagnosis4.6 years3 years-Not mentioned5 yearsNot mentionedNot mentioned
Initial symptomsMyoclonic seizuresUnsteady gait and frequent fallsSpeech delay Ataxic gaitSeizuresIncreasing clumsinessDelayed speech developmentMotor regression + worsening gate
Clinical presentationsMyoclonic seizures Cognitive, speech, and motor regression Ataxic gait Visual impairmentSeizures Motor, speech, and cognitive regression Ataxic gait Visual impairmentSpeech delay Motor and cognitive regression Seizures Visual impairmentSeizures Motor, cognitive and speech regression Ataxic gait Autism-like Visual impairment DysphagiaDevelopmental delay Speech, psychomotor and cognitive regression Visual impairment SeizuresSpeech delay seizures Motor and cognitive regression Visual failure Behavioral changesLanguage delay Ataxic gait Motor regression Seizures Visual impairment Dysphagia
Type of seizuresMyoclonic SeizuresMyoclonic Seizures GTCMyoclonic Seizures GTCRefractory SeizuresComplex partial seizuresMyoclonic SeizuresMyoclonic Seizures Drop attack
Motor disabilityChair bound by age of 5 yearsChair bound by age of 4 yearsBedridden by age of 6 yearsBedridden by age of 8.6 yearsChair bound by age of 5.5 yearsBedridden by age of 8 yearsChair bound by age of 5.9 years
Neurophysiology (EEG, VEP, ERG)EEG: diffuse slow background with generalized epileptiform discharges. ERG: normal VEP: reducedEEG: diffuse slow background activity with generalized epileptiform discharges. ERG: absent VEP: reducedEEG: Diffuse slow background activity with generalized epileptiform discharges. ERG & VEP: not doneEEG: irregular and slow background activity with generalized sequences of atypical spike-wave discharges. ERG & VEP: not mentionedEEG: slow background, complex partial seizures ERG: absent VEP: reducedEEG: spileptic discharges with generalized polyspike wave activity. ERG &VEP: not mentionedEEG: not mentioned VEP: abnormal ERG: absent
Neuro imagingMRI: cerebellar atrophyMRI: cerebral and cerebellar atrophyMRI: cerebellar atrophyMRI: cerebral and cerebellar atrophyMRI: hyperintensity of white matter and cerebellar atrophy.MRI: cerebral and cerebellar atrophyCerebellar atrophy, low signal change abnormality in thalami bilaterally
Genetic studyCLN8 c.(?_-1)(543+1_544-1)del spans exon 1C.699-700delGT pPhe234Profs*12 del spans exon 2Deceased before.Two variants: c.298 C > T (p.Gln100Ter); c.551 G > A(p.Trp184Ter)c.562_563delCT, p.(Leu188Valfs*58) (paternal); 8p23.3 terminal deletion, de novoc.544-2566_590del2613Hemizygous for a novel variant: 54 kb deletion (paternal); c.728T>C P.(Leu243Pro) (maternal)
locationExon1Exon2-Exon2 & Exon3Exon 3In3/Exon3Not mentioned
Age of deathAliveAlive8 yearsAlive at age of 8 yearsAlive at age of 5.5 yearsBoth alive at 10 years9 years