Objective: To investigate the genotype and phenotype of children with KCNA2 gene related developmental and epileptic encephalopathy (DEE). Methods: Clinical data including the manifestations and electroencephalogram of 8 children with KCNA2 variants treated in the Department of Pediatrics, Peking University First Hospital from March 2017 to June 2019 were collected and analyzed retrospectively. Results: Among the 8 epileptic patients with KCNA2 variants, 5 were males and 3 were females. The age of onset was from 1 day to 11 months. The age at last follow-up ranged from 4 months to 86 months. Two variants including c.1214C>T (loss-of-function) and c.1120A>G (gain-and loss-of-function) were identified. The variant of c.1214C>T was found in six patients (case 1-6). For these patients, the age of onset was from 5 to 11 months and they were characterized by multiple seizure types. All had focal seizures and had normal development before seizure onset with developmental regression after seizure onset. The first electroencephalogram showed epileptic discharges in Rolandic region in two, epileptic discharges in Rolandic region combined with generalized discharge in one, generalized discharge with posterior predominance in two (combined with or transferred to Rolandic region during the course) and epileptic discharges in posterior region combined with generalized discharge in one. And in 5 of them the Rolandic discharges developed into epileptic electrical status (ESES) during sleep. All the six patients were still treated with a combination of multiple antiepileptic drugs. Two of them had seizure controlled at 80 months and 68 months, respectively. The variant of c.1120A>G were identified in two of eight patients (case 7 and 8) and they had seizure onset on the 1st day after birth. Their epileptic seizures were frequent and difficult to control. They had remarkably developmental delay and microcephaly since birth. One case (case 8) had a wide forehead. They had frequent seizures up to the last follow-up. In case 7, the early electroencephalogram showed epileptic discharges in temporal region, and interictal electroencephalogram at 3 months of age showed multifocal discharge with posterior and temporal region predominance. In case 8, the early electroencephalogram was normal and electroencephalogram showed burst suppression at 2 months of age, and it developed epileptiform discharge in posterior region at 1 year of age. Conclusions KCNA2 gene variants can lead to DEE with multiple seizures types. Among them, loss-of-function c.1214C>T is the most common, and these patients have seizure onset at infancy with Rolandic discharges tended to develop into to ESES pattern. The variant of c.1120A>G is a gain-of- and loss-of-function variant, patients with c.1120A>G have seizure onset in neonatal period, the phenotype overlaps with the former but is more severe.

Objective:To analyze the clinical phenotype and genetic characteristics of children with germline PIGA gene mutations. Methods:The clinical presentations, blood biochemistry, electroencephalogram (EEG), brain magnetic resonance imaging (MRI) and genetic test results of 10 children diagnosed at the Department of Pediatrics of Peking University First Hospital between January 2014 and June 2020 were analyzed.Results:All these 10 children were male, with seizures and severe developmental delay.Five out of eight cases showed hypotonia.Four out of nine cases had facial deformity or multiple organ abnormalities.The onset age of seizures ranged from one month and 28 days to 10 months, with an average age of 4.8 months.There were various types of seizures, and all patients showed focal seizures.The seizures of 6 patients in these 10 cases could be induced by fever disease.Diffuse slow waves mixed focal or multifocal discharges of interictal EEG in 9 cases with PIGA-deficient.Brain MRI showed enlarged subarachnoid space in 44.4% (4/9 cases) of patients.Slight elevated serum alkaline phosphatase could be seen in 2 cases.Genetic analysis confirmed that a total of 8 different mutation sites were found, 7 of which were unreported.In this group, 4 cases were diagnosed with multiple congenital anomalies -hypotonia -seizures syndrome 2 (MCAHS2), 5 cases were diagnosed with developmental delay and epilepsy without deformity, and one case was not classified, respectively. Conclusions:Focal seizure was common in these patients with PIGA mutations, and often induced by fever disease.Interictal EEG was characterized by diffuse slow waves mixed focal or multifocal discharges.Enlarged subarachnoid space was the most common brain MRI abnormality in these patients.The phenotype of patients only partially conformed to typical MCAHS2 manifestations, and most of them had no deformity.

Objective:To analyze the clinical phenotype and genotype characteristics of infantile spasm (IS) associated with UBA5 gene mutation. Methods:Four cases of IS caused by UBA5 gene variation diagnosed at the Department of Pediatrics, Peking University First Hospital from March 2017 to June 2019 were retrospectively analyzed.The clinical manifestations, electroencephalogram (EEG), brain magnetic resonance imaging (MRI), treatment, and follow-up results were summarized. Results:In this study, 4 cases (3 males and 1 female) were clinically diagnosed with IS and carried complex heterozygous variation of UBA5 gene.Genetic analysis confirmed that a total of 6 different mutation sites were found, five of which were unreported.All the 4 cases presented with epileptic spasms at the age of 1 d to 8 months after birth, and 2 cases had focal seizures during the course of disease.The EEG of 4 cases showed hypsarrhythmia and cluster or isolated epileptic spasms were detected.Of the 3 patients who had brain MRI results, 2 cases showed nonspecific abnormalities and 1 case was normal.All the 4 patients had developmental delayed before seizure onset, and regressed to varying degrees and made slow progress after onset.One case had microcephaly, and 3 cases had hypertonia.At the last follow-up, the age of the 4 patients ranged from 7 months to 6 years and 4 months.All 4 patients were treated with multiple antiepileptic drugs, but none of them were under control. Conclusions:Children with IS associated with UBA5 gene variation have an early onset age, often accompanied by developmental delayed, microcephaly, dystonia, and refractory seizures.

Objective:To investigate the clinical and electroencephalographic characteristics of photosensitive occipital lobe epilepsy (POLE) in children.Methods:The clinical data, electroencephalogram (EEG), treatment and prognosis of 22 children with POLE in the Department of Pediatrics, Peking University First Hospital from January 2006 to December 2019 were retrospectively analyzed.Results:Among the 22 patients, 12 cases were female and 10 cases were male.There were 3 cases combined with mild mental retardation.Classified by seizure symptoms, only 3 patients complained of subjective symptoms of visual aura, and the common symptoms were eye movement in 11 patients, headache in 3 patients, vomiting in 6 patients and dizziness in 3 patients.All patients had focal seizures during the course of disease.Twenty patients had secondary bilateral tonic-clonic seizures, and 5 patients also had generalized myoclonic seizures.Interictal epileptiform discharges were monitored in EEG of all children, including pure focal discharges in 6 patients, pure generalized discharges in 10 patients, and coexistence of generalized and focal discharges in 6 patients.Photoparoxysmal responses were induced in 19 patients, including pure focal discharges in 4 patients, pure generalized discharges in 6 patients, and coexisting focal and generalized discharges in 9 patients.Photoconvulsive responses were induced in 16 patients, including focal seizures with occipital lobe onset or focal secondary to bilateral tonic-clonic seizures in 15 patients, and myoclonic seizures in 1 patient.Eighteen patients were treated with anti-seizure medications (ASMs) and followed up.The top 3 commonly used drugs were Valproic acid (12 patients), Levetiracetam (8 patients), and Lamotrigine (4 patients), and 13 cases had controlled seizures.Conclusions:The visual aura of POLE is not obvious, and the relationship between epilepticseizures and light stimuli in daily life should be actively inquired to avoid misdiagnosis or underdiagnosis of the syndrome.The EEG of POLE often visualizes the coexistence of focal and generalized discharges, which may be accompanied by generalized seizures.The coexistence phenomenon should be considered when ASMs are medicated during treatment, and odium channel blockers should be selected carefully.