[Clinical characteristics of epileptic seizure in neurofibromatosis type 1 in 15 cases].

Objective: To summarize the clinical characteristics of epileptic seizure associated with neurofibromatosis type 1 (NF1). Methods: From January 2017 to July 2023 at Children's Hospital Capital Institute of Pediatrics, medical records of patients with both NF1 and epileptic seizure were reviewed in this case series study. The clinical characteristics, treatment and prognosis were analyzed retrospectively. Results: A total of 15 patients(12 boys and 3 girls) were collected. Café-au-lait macules were observed in all 15 patients. There were 6 patients with neurodevelopmental disorders and the main manifestations were intellectual disability or developmental delay. The age at the first epileptic seizure was 2.5 (1.2, 5.5) years. There were various seizure types, including generalized tonic-clonic seizures in 8 patients, focal motor seizures in 6 patients, epileptic spasm in 4 patients, tonic seizures in 1 patient, absence in 1 patient, generalized myoclonic seizure in 1 patient and focal to bilateral tonic-clonic seizure in 1 patient. Among 14 patients whose brain magnetic resonance imaging results were available, there were abnormal signals in corpus callosum, basal ganglia, thalamus or cerebellum in 6 patients, dilated ventricles of different degrees in 3 patients, blurred gray and white matter boundary in 2 patients, agenesis of corpus callosum in 1 patient and no obvious abnormalities in the other patients. Among 13 epilepsy patients, 8 were seizure-free with 1 or 2 antiseizure medications(ASM), 1 with drug resistant epilepsy was seizure-free after left temporal lobectomy, and the other 4 patients who have received 2 to 9 ASM had persistent seizures. One patient with complex febrile convulsion achieved seizure freedom after oral administration of diazepam on demand. One patient had only 1 unprovoked epileptic seizure and did not have another seizure without taking any ASM. Conclusions: The first epileptic seizure in NF1 patients usually occurs in infancy and early childhood, with the main seizure type of generalized tonic-clonic seizure and focal motor seizure. Some patients have intellectual disability or developmental delay. Most epilepsy patients achieve seizure freedom with ASM.

[A case of intellectual developmental disorder with behavioral abnormalities and craniofacial dysmorphism with or without seizures caused by PHF21A gene variation and review of literature].

Objective: To discuss the clinical and genetic features of intellectual developmental disorder with behavioral abnormalities and craniofacial dysmorphism with or without seizures (IDDBCS). Methods: The clinical and genetic records of a patient who was diagnosed with IDDBCS caused by PHF21A gene variation at Children's Hospital Capital Institute of Pediatrics in 2021 were collected retrospectively. Using " PHF21A gene" as the keyword, relevant articles were searched at CNKI, Wanfang Data and PubMed from establishment of databases to February 2023. Clinical and genetic features of IDDBCS were summarized in the combination of this case. Results: An 8 months of age boy showed overgrowth (height, weight and head circumference were all higher than the 97th percentile of children of the same age and sex) and language and motor developmental delay after birth, and gradually showed autism-like symptoms like stereotyped behavior and poor eye contact. At 8 months of age, he began to show epileptic seizures, which were in the form of a series of spastic seizures with no reaction to adrenocorticotropic hormone but a good response to vigabatrin. Physical examination showed special craniofacial appearances including a prominent high forehead, sparse eyebrows, broad nasal bridge, and downturned mouth with a tent-shaped upper lip. The patient also manifested hypotonia. Whole exome sequencing showed a de novo heterogeneous variant, PHF21A (NM_001101802.1): c.54+1G>A, and IDDBCS was diagnosed. A total of 6 articles (all English articles) were collected, involving this case and other 14 patients of IDDBCS caused by PHF21A gene variation. Clinical manifestations were intellectual disability or developmental delay (15 patients), craniofacial anomalies (15 patients), behavioral abnormalities (12 patients), seizures (9 patients), and overgrowth (8 patients). The main pathogenic variations were frameshift variations (8 patients). Conclusions: IDDBCS should be considered when patients show nervous developmental abnormalities, craniofacial anomalies, seizures and overgrowth. PHF21A gene variation detection helps to make a definite diagnosis.

[A case of combined oxidative phosphorylation deficiency 32 caused by MRPS34 gene variation and literature review].

Objective: To investigate the clinical features and genetic features of combined oxidative phosphorylation deficiency 32 (COXPD32) caused by MRPS34 gene variation. Methods: The clinical data and genetic test of a child with COXPD32 hospitalized in the Department of Neurology, Children's Hospital, Capital Institute of Pediatrics in March 2021 were extracted and analyzed. A literature search was implemented using Wanfang, China biology medicine disc, China national knowledge infrastructure, ClinVar, human gene mutation database (HGMD) and Pubmed databases with the key words "MRPS34" "MRPS34 gene" and "combined oxidative phosphorylation deficiency 32" (up to February 2023). Clinical and genetic features of COXPD32 were summarized. Results: A boy aged 1 year and 9 months was admitted due to developmental delay. He showed mental and motor retardation, and was below the 3rd percentile for height, weight, and head circumference of children of the same age and gender. He had poor eye contact, esotropia, flat nasal bridge, limbs hypotonia, holding instability and tremors. In addition, Grade Ⅲ/6 systolic murmur were heard at left sternal border. Arterial blood gases suggested that severe metabolic acidosis with lactic acidosis. Brain magnetic resonance imaging (MRI) showed multiple symmetrical abnormal signals in the bilateral thalamus, midbrain, pons and medulla oblongata. Echocardiography showed atrial septal defect. Genetic testing identified the patient as a compound heterozygous variation of MRPS34 gene, c.580C>T (p.Gln194Ter) and c.94C>T (p.Gln32Ter), with c.580C>T being the first report and a diagnosis of COXPD32. His parents carried a heterozygous variant, respectively. The child improved after treatment with energy support, acidosis correction, and "cocktail" therapy (vitaminB1, vitaminB2, vitaminB6, vitaminC and coenzyme Q10). A total of 8 cases with COXPD32 were collected through 2 English literature reviews and this study. Among the 8 patients, 7 cases had onset during infancy and 1 was unknown, all had developmental delay or regression, 7 cases had feeding difficulty or dysphagia, followed by dystonia, lactic acidosis, ocular symptoms, microcephaly, constipation and dysmorphic facies(mild coarsening of facial features, small forehead, anterior hairline extending onto forehead,high and narrow palate, thick gums, short columella, and synophrys), 2 cases died of respiratory and circulatory failure, and 6 were still alive at the time of reporting, with an age range of 2 to 34 years. Blood and (or) cerebrospinal fluid lactate were elevated in all 8 patients. MRI in 7 cases manifested symmetrical abnormal signals in the brainstem, thalamus, and (or) basal ganglia. Urine organic acid test were all normal but 1 patient had alanine elevation. Five patients underwent respiratory chain enzyme activity testing, and all had varying degrees of enzyme activity reduction. Six variants were identified, 6 patients were homozygous variants, with c.322-10G>A was present in 4 patients from 2 families and 2 compound heterozygous variants. Conclusions: The clinical phenotype of COXPD32 is highly heterogenous and the severity of the disease varies from development delay, feeding difficulty, dystonia, high lactic acid, ocular symptoms and reduced mitochondrial respiratory chain enzyme activity in mild cases, which may survive into adulthood, to rapid death due to respiratory and circulatory failure in severe cases. COXPD32 needs to be considered in cases of unexplained acidosis, hyperlactatemia, feeding difficulties, development delay or regression, ocular symptoms, respiratory and circulatory failure, and symmetrical abnormal signals in the brainstem, thalamus, and (or) basal ganglia, and genetic testing can clarify the diagnosis.

[Clinical and genetic characteristics of children with STXBP1 encephalopathy].

Objective: To investigate the clinical and genetic characteristics of developmental and epileptic encephalopathy (DEE) caused by syntaxin-binding protein 1 (STXBP1) gene mutation. Methods: The clinical data, gene variation and treatment outcome of 15 children with STXBP1 encephalopathy admitted to Children's Hospital Affiliated to Capital Institute of Pediatrics from January 2014 to June 2019 were analyzed retrospectively. Results: Among 15 patients, 11 were male and 4 were female, age ranged from 2 months to 69 months. The clinical manifestations of 14 children were epilepsy and developmental delay (DD) and the remaining one showed developmental delay without seizure. The onset age of epilepsy ranged from two days to 19 months and 11 of them experienced the first attack before 1 year of age. The common seizure types were epileptic spasms and tonic seizures. Seven patients were diagnosed with Ohtahara syndrome or West syndrome. Epileptic form discharges were observed in the interictal electroencephalograms (EEG) of 11 patients, including multifocal discharges, suppression-burst and hypsarrhythmia. The brain magnetic resonance imaging of 7 children were abnormal, including myelin dysplasia, less white matter, lack of corpus callosum or hypoplasia. The follow-up time ranged from 2 months to 57 months, after the last follow-up, 3 cases were seizure free, 6 children showed partial response and the other 5 patients had no response on multitherapy. Six of 8 patients showed good responses to levetiracetam (LEV) monotherapy or in combination with other antiepileptic drugs (AEDs). Vigabatrin (VGB) was applied to 5 patients with epileptic spasms and 4 of them showed response. All patients showed different degrees of developmental delay while four of them showed autistic features. STXBP1 gene mutations were identified in all cases and there were 15 types of gene variations, including 8 missense mutations, 1 nonsense mutation, 5 frame shift mutations and 1 complex mutation. Five novel mutations were unreported before, including c.1193A>G, c.172delG, c.1769C>T, c.1038_1039delCC, c.348_351dupTGAA. Conclusions: Development delay and epilepsy are the major and independent clinical phenotypes in children with STXBP1 encephalopathy. The variation of STXBP1 gene is mainly de novo. Levetiracetam and vigabatrin may be more effective in epilepsy control than other AEDs.

[A phenotypic and genetic study on ß-propeller protein-associated neurodegeneration].

Objective: To summarize the clinical and genetic features of ß-propeller protein-associated neurodegeneration (BPAN). Methods: The clinical data of 17 patients with BPAN with WDR45 gene variants were retrospectively collected at Children's Hospital of Fudan University, Peking University First Hospital, Capital Institute of Pediatrics, Shengjing Hospital of China Medical University and Shanghai Children's Hospital from June 2016 to December 2018, and their clinical manifestations, electroencephalogram, neuroimaging and genetics were analyzed. Results: Seventeen cases (13 females, 4 males), aged 1.1-8.8 years, were included. The median age of seizure onset was 14.5 months, from 3 months to 24 months of age, manifested with epileptic spasm in 6 cases and focal seizures in 5 cases. Eight patients had only one seizure type and 8 patients had two or more seizure types. Nine patients had complete remission of seizures. All 16 patients with seizures had developmental delay before the seizure onset, of whom 13 patients had moderate to severe seizures. The brain magnetic resonance imaging (MRI) was abnormal in 13 patients, including cerebral atrophy (10 cases) and thinning of the corpus callosum (9 cases). The brain magnetic susceptibility weighted imaging (SWI) in preschool stage showed prominent T2 hypointense signals in bilateral globus pallidus and brainstem ventral in two cases. Five seizure types (spasm, focal, absence, myodonic and generalized tonic clonic seizures)were found on ictal electroencephalogram(EEG) recordings. Compared to female patients(17(6-24) months of ege), male cases had earlier seizure onset (3, 4, 5, 18 months of age) . All patients had de novo variations in WDR45(6 nonsense, 4 frameshift, 3 missense and 4 splicing variations), with hemizygous variants in 3 males, mosaic variants in a male and heterozygous variants in 13 females, within which 5 variations had not been reported (c.977-1C>T,c.976+1G>C,c.10C>T,c.806del and c.110T>C). Conclusions: The patients with BPAN have profound developmental delay and are vulnerable to seizures. The male patients with BPAN tend to have more severer clinical phenotype than females. Early brain SWI could facilitate the timely diagnosis of this disease.

[Study of de novo point mutations in known genes among patients with unexplained intellectual disability or developmental delay].

Objective: To analyze the de novo point mutations in known genes among patients with unexplained intellectual disability (ID) or developmental retardation (DD). Methods: A total of 120 outpatients with ID or DD were recruited in the Department of Neurology, Affiliated Children's Hospital of Capital Institute of Pediatrics between September 2015 and April 2017. Target gene sequencing was used to screen the candidate gene. The sequencing data were analyzed by a variety of bioinformatics software. Combining with the phenotypes of the patients, the candidate genetic/genomic variants were identified from next-generation sequencing data. The final pathogenicity of the genetic/genomic variants were interpreted according to the guideline of the American College of Medical Genetics and Genomics (ACMG) for variants after segregation analysis in the parents and necessary family members by Sanger sequencing. The comprehensive physiological function and signaling pathways of 20 disease genes with de novo point mutation discovery was also studied. Results: Among the 120 patients, 23 patients were found to carry clear pathological changes, and the incidence of de novo point variation was 19.2%. The patients included 12 males and 11 females, with an age of 2 months to 6-year-6-month. Five patients were diagnosed with early onset of epileptic encephalopathy. Seven had mental retardation type 5, 6, 8, 19, 20, 22, 39, respectively. Weill-Marchesani syndrome type 2 was found in one case, Wiedemann-Steiner syndrome in one case, Coffin-Siris syndrome in two cases, Rubinstein-Taybi syndrome in one case, GLUT1 deficiency syndrome in one case, Rett syndrome in one case, cardio-facio-cutaneous syndrome 3 in one case, neurodegeneration with brain iron accumulation in one case, corpus callosum local dysplasia in one case, and congenital fibrosis of the extra-ocular muscles in one case. A total of 20 novel mutations were reported in this study. No somatic mutation was found in the samples of 6 patients with mutation and their parents' peripheral blood DNA samples by amplicon-based deep sequencing. This study found that the main disease genes were involved in chromatin remodeling, transcriptional regulation, autophagy body assembly, MAPK signal pathway, DNA methylation, potassium, sodium ion transport, cell skeleton assembly and skeletal muscle development. These genes were significantly enriched in the following biological processes: Ras signaling pathways, transcription factor binding and cancer related signaling pathway. Conclusions: The etiology of children affected with intellectual disability or developmental delay is complex. Harmful de novo point mutation plays an important role in these diseases. Targeted exome/genome sequencing based on the core family is helpful for the molecular diagnosis of patients and the discovery of more genes.