Mitochondrial and peroxisome fission deficiency-related encephalopathy caused by DNM1L gene mutation is a rare and fatal epileptic encephalopathy, with clinical phenotype and genetic heterogeneity. The acute stage is drug-resistant epilepsy with poor prognosis and serious neurological sequelae. A case of genetically confirmed encephalopathy related to mitochondrial and peroxisome fission defects is reported, the clinical data, treatment process are summarized, and the previous literature is reviewed to improve the understanding of the rare disease.

Objective:To explore the clinical phenotypic features and genetic variation characteristics of children with epilepsy-aphasia spectrum due to GRIN2A gene variants confirmed by second-generation sequencing. Methods:The clinical data of 5 children with epilepsy-aphasia spectrum with epileptic onset diagnosed in the Department of Neurology, Children′s Hospital Affiliated to Zhengzhou University, from February 2019 to November 2022 were retrospectively analyzed. Whole-exome genome sequencing of the probands using a second-generation sequencing method confirmed that all 5 cases were children with the GRIN2A gene variant. The characteristics of the GRIN2A gene variants were analyzed. Results:Among the 5 children diagnosed with epileptic aphasia spectrum due to GRIN2A gene variants, the male-to-female ratio was 4∶1, and the age range of onset was 1.5-4.4 years. The clinical phenotype included seizures in all cases, language and intellectual developmental deficits in 4 cases, and attention deficit hyperactivity disorder in 3 cases. The seizures were manifested as focal seizures or secondary generalized seizures, and were effectively controlled with antiepileptic drugs. Among the 5 children, gene variant of case 1 was originated from a paternal heterozygous variant, and cases 2-5 had de novo variants, which were c.2107C>T (p.Gln703 *) nonsense variant, c.2284G>A (p.Gly762Arg) missense variant, c.2197del (p.Ala733Glnfs *3) shifted coding variant, c.2511G>A (p.Trp837 *) nonsense variant, and c.1651+1G>C shear site variant, respectively. None of the 5 loci were reported in the literature. Conclusions:Epilepsy-aphasia spectrum is an epilepsy syndrome with a complex onset, and may have different phenotypes at different genetic variant loci, with focal seizures or secondary generalized seizures, which can be effectively controlled with anti-seizure medication. The GRIN2A gene variant is the genetic etiology of the epileptic aphasia spectrum.

The clinical data and gene variant characteristics of a patient with glutathione synthetase (GSS) deficiency were summarized. The child was born 15 min prematurely as a male infant with postnatal respiratory distress, metabolic acidosis, severe anemia, hemolysis, hyperbilirubinemia, and motor developmental backwardness. Blood and urine genetic metabolic screening showed a blood glutamate value of 1 343.1 μmol/L and a urine 5-oxoproline value of 1 873.7 nmol/mg creatinine. Cranial magnetic resonance imaging showed nonspecific subarachnoid widening. Whole-exon gene sequencing of the family line suggested that the GSS gene of the preexisting patient originated from paternal and maternal variants, respectively: c.632_633del (p.Gln211Argfs *8), and c.491G>A (p.Arg164Gln). Complex heterozygous variants of the GSS gene were the genetic etiology of the present case.

OBJECTIVE: To analyze the clinical phenotype and genetic variant of a child with Snijders Blok-Campeau syndrome (SBCS). METHODS: A child who was diagnosed with SBCS in June 2017 at Henan Children's Hospital was selected as the study subject. Clinical data of the child was collected. Peripheral blood samples of the child and his parents were collected and the extraction of genomic DNA, which was subjected to trio-whole exome sequencing (trio-WES) and genome copy number variation (CNV) analysis. Candidate variant was verified by Sanger sequencing of his pedigree members. RESULTS: The main clinical manifestations of the child have included language delay, intellectual impairment and motor development delay, which were accompanied with facial dysmorphisms (broad forehead, inverted triangular face, sparse eyebrows, widely spaced eyes, narrow palpebral fissures, broad nose bridge, midface hypoplasia, thin upper lip, pointed jaw, low-set ears and posteriorly rotated ears). Trio-WES and Sanger sequencing revealed that the child has harbored a heterozygous splicing variant of the CHD3 gene, namely c.4073-2A>G, for which both of his parents were of wild-type. No pathogenic variant was identified by CNV testing. CONCLUSION The c.4073-2A>G splicing variant of the CHD3 gene probably underlay the SBCS in this patient.
DNA Copy Number Variations ; Heterozygote ; Pedigree ; Phenotype ; RNA Splicing ; Mutation

Objective:To explore the effects of the compound ICG-001 on autism-like behaviors and the morphological development of dendritic spines in hippocampal pyramidal neurons of rats.Methods:Healthy Wistar rats were mated.The offspring were divided into the saline-treated group, ICG-001 control group, Sodium valproate (VPA) group and ICG-001 treatment group by using the random number table method.Each group had 12 rats.Social interaction, repetitive, compulsive and anxiety-like behaviors in rodents were assessed by three-chambered social approach, marble burying, open-field and elevated plus maze tests.The number of neuronal nuclei (NeuN)-positive neurons in the hippocampal CA1 region was calculated by the immunofluorescence method.Golgi staining was carried out to detect the density and morphological changes of dendritic spines in hippocampal pyramidal neurons of rats.The expression of phosphorylated LIM kinase 1(LIMK1), phosphorylated actin binding protein(Cofilin), fibros actin (F-actin) and developmentally-regulated brain protein A (Drebrin A) was examined by Western blot.The univariate analysis was made to examine whether the difference was statistically significant, and the data between groups were compared by the Tukey method. Results:(1) In the three-chambered social approach test, the rats in the saline-treated group, ICG-001 control group, VPA group and ICG-001 treatment group spent (219.42±5.38) s, (218.67±10.12) s, (126.58±5.02) s, and (218.58±6.63) s in the chamber, respectively.The corresponding preference score of the said 4 groups were 0.43±0.05, 0.43±0.04, 0.22±0.01 and 0.42±0.04, respectively.Compared with the VPA group, the ICG-001 treatment group spent longer time in the chamber and had a higher preference score (all P<0.05). (2) In the marble burying experiment, the number of marbles buried in said 4 groups were 9.13±0.52, 9.08±0.64, 15.13±0.82 and 9.42±0.86, respectively.ICG-001-treated rats buried markedly less marbles than VPA-exposed rats ( P<0.05). (3) In the open-field test, the rats in the said 4 groups spent (82.33±1.83) s, (81.32±4.19) s, (45.51±3.02) s and (81.44±3.19) s in the center area, respectively.Administration of ICG-001 significantly increased the time that VPA-exposed rats spent in the center area ( P<0.05). (4)In the elevated plus maze trial, the rats in the said 4 groups spent (107.75±7.23) s, (106.08±7.50) s, (63.42±1.91) s and (106.67±7.07) s in open arms, respectively.ICG-001 treatment notably increased the time that VPA-exposed rats spent in open arms ( P<0.05). (5) Immunofluorescence analysis results revealed that the number of NeuN-positive cells in the hippocampal CA1 region of said 4 groups was (41.83±1.17)×10 4/μm 2, (41.00±0.77)×10 4/μm 2, (27.17±0.95)×10 4/μm 2 and (40.00±0.90)×10 4/μm 2, respectively.ICG-001 treatment normalized the alteration in the number of NeuN-containing neurons in VPA-exposed rats ( P<0.05). (6) Golgi staining showed that the density of dendritic spines in hippocampal CA1 pyramidal neurons of said 4 groups was (0.74±0.04)/μm, (0.73±0.03)/μm, (0.49±0.03)/μm and (0.70±0.02) /μm, respectively.Of all types of dendritic spines, mushroom spines accounted for (0.49±0.02)%, (0.49±0.02)%, (0.33±0.02)% and (0.43±0.02) % in said 4 groups.Thin spines accounted for (0.27±0.02)%, (0.26±0.02)%, (0.34±0.01)% and (0.26±0.01) % in said 4 groups, respectively.Compared with the VPA group, the ICG-001 treatment group showed a significant increase in the density of dendritic spines in hippocampal CA1 pyramidal neurons ( P<0.05). After ICG-001 treatment, the number of mushroom spines greatly increased and the number of thin spines sharply decreased in VPA-exposed rats (all P<0.05). (7) According to Western blot test results, the phosphorylated LIMK1/LIMK1 ratio of the hippocampus in said 4 groups were 100.33±2.30, 99.34±2.28, 57.76±4.10 and 99.13±1.90, respectively.The phosphorylated Cofilin /Cofilin ratio were 100.18±2.43, 100.18±1.70, 57.12±1.88 and 99.53±1.69, respectively.The F-actin/globular actin(G-actin) ratio were 100.07±0.86, 99.99±1.72, 51.19±1.23 and 99.28±3.17, respectively.The expression level of Drebrin A were 100.79±1.19, 100.12±2.04, 52.86±3.26 and 99.97±2.44, respectively.Administration of ICG-001 effectively prevented the decrease of phosphorylated LIMK1, phosphorylated Cofilin, F-actin and Drebrin A in the hippocampus of VPA-exposed rats (all P<0.05). Conclusions:ICG-001 regulates the LIMK1/Cofilin signaling pathway, promotes the generation of F-actin, increases the expression of Drebrin A, and thereby alleviates autistic-associated symptoms.

Objective:To analyze the clinical characteristics and genetic variation of 2 children with developmental and epileptic encephalopathy 8 (DEE8).Methods:Whole-exome sequencing (WES) was performed to determine the potential variants in the probands. Candidate variants identified by WES were validated by Sanger sequencing and quantitative real-time polymerase chain reaction. X chromosome inactivation (XCI) detection was performed in the proband 1′s mother and proband 2 to detect the allelic expression difference of ARHGEF9. Results:Both of the cases showed global developmental delay. Proband 1 presented with delayed motor and speech development, intellectual disability, and seizures. Electroencephalography of proband 1 showed slow background activity, with spikes, spike and waves in bilateral frontal and midline regions during sleep. While proband 2 showed delay in acquisition of language, motor skills, and cognition, but no seizures. It was identified that proband 1 carried a novel maternally derived heterozygous splicing variant (c.925-2A>T) in ARHGEF9 by WES, which was verified in Sanger sequencing. The XCI in proband 1′s mother was observed, and the expression ratio of mutant ARHGEF9 and wild-type was 0∶100%. A novel exon 3-10 heterozygous deletion of ARHGEF9 was identified in proband 2, and this variant was not found in his unaffected parents. Conclusions:DEE8 disorders are relatively rare. Most of the patients have varying degrees of neurodevelopmental phenotype, but epilepsy is not a specific clinical manifestation. ARHGEF9 gene deletion and splicing variation may be the genetic cause of the 2 probands, and above findings have enriched the spectrum of variation and phenotype of DEE8.

Objective:To summarize the clinical phenotype and genetic characteristics of Poirier-Bienvenu neurodevelopmental syndrome associated with CSNK2B gene variation. Methods:The clinical and genetic data of a child with Poirier-Bienvenu neurodevelopmental syndrome caused by shear variant of CSNK2B gene who was diagnosed in the Department of Neurology, Children′s Hospital Affiliated to Zhengzhou University in March 2022 were collected. Previous relevant literature at home and abroad was reviewed to summarize the clinical characteristics of the disease. Results:The child was a girl aged 13 months, mainly due to "intermittent convulsions for 2 months" for consultation. The clinical manifestations of the girl were normal face, generalized tonic-clonic seizures, low intelligence, language and motor retardation, and there was no abnormality in the long-range video electroencephalography and the head magnetic resonance imaging. No abnormality was found in chromosome karyotype analysis and chromosome coefficient of copy variation analysis. The whole exon gene sequencing test indicated that the child carried de novo heterozygous shear variant of CSNK2B gene c.291+5G>C, which had not been reported in the literature. According to the clinical manifestations and genetic examination results of the child, the diagnosis of Poirier-Bienvenu neurodevelopmental syndrome was clear. The CSNK2B gene of the proband′s parents and the twin sister was wild-type. The application of sodium valproate anti-seizure medication could effectively control the seizures of the child, and by giving rehabilitation function training, the child′s language and gross motor function was improved. Conclusions:The Poirier-Bienvenu neurodevelopmental syndrome is a rare autosomal dominant disorder caused by variants in the CSNK2B gene. The clinical manifestations are infancy-onset seizures, intellectual development disorders, language and motor development disorders, etc, and the video electroencephalogram and skull magnetic resonance are mostly normal. The CSNK2B gene shear variant is the genetic etiology of the proband.

Objective:To investigate the clinical characteristics of patients with combined oxidative phosphorylation deficiency type 4 (COXPD4) related to TUFM gene variation, in order to improve clinicians′ understanding of the disease. Methods:A case of COXPD4 with cystic leukodystrophy admitted to the Children′s Hospital of Zhengzhou University in June 2021 was taken as the study subject, and her clinical characteristics and genetic testing results were retrospectively analyzed. The "combined oxidative phosphorylation deficiency type 4" " TUFM gene" "cystic leukodystrophy" "combined oxidative phosphorylation deficiency 4" "COXPD 4" " TUFM" and "cystic leukodystrophy" were used as keywords, and the documents on COXPD4 related to TUFM gene mutations were reviewed from Wanfang Data Knowledge Service Platform, CNKI, PubMed Document Database, and National Center for Biotechnology Information (NCBI) until August 2021. The COXPD4 patients that have been reported internationally were analyzed for clinical features and variant types. Results:The patient was a 2-month-old girl with clinical manifestations of delayed development and progressive aggravation, elevated lactic acid in serum and cerebrospinal fluid, and diffuse white matter dysplasia with multiple cystic lesions in cerebral magnetic resonance imaging (MRI). Whole exome sequencing showed TUFM gene complex heterozygous variants c.684_684+4delGGTGA and c.1105C>T, which had not been reported in the past. A total of 5 cases of COXPD4 were reported in 4 English literatures. Together with 1 case in this study, there were 4 cases with detailed clinical history data, including 1 male and 3 females. The clinical manifestations were severe early-onset lactic acidosis and developmental lag, and 3 cases were accompanied by progressive infantile encephalopathy. Among them, 3 cases underwent head MRI examination, all of which showed diffuse white matter signal with multiple cystic lesions, 2 cases with basal ganglia involvement and multiple cerebellar gyri deformity. Genetic test indicated different types of TUFM gene variation. Conclusions:COXPD4 is a rare hereditary mitochondrial disease. For cases with COXPD4 clinical and imaging features, TUFM gene mutations can be screened first.

Clinical data and genetic mutation characteristics of a patient with Coffin-Siris syndrome by 6q25.3 deletion were summarized. The child was a 7-year and 6-month old girl who had feeding difficulties, repeated infection, language and motor retardation, low intelligence, laryngeal cartilage dysplasia, thick eyebrows, sparse teeth, hairy back, hyperactivity and aggressive behavior, seizures and ataxia. There was no abnormality in chromosomal karyotype analysis by proband; genomic copy number variant sequencing (CNV-seq) indicated approximately 4.27 Mb heterozygous deletion in chromosome 6q25.3 region, with 17 genes including ARID1B gene, father maternal CNV-seq showing no abnormalities. Trio-whole-exome sequencing showed the proband missed all exons 1-20 of the ARID1B gene, with wild-type parents. The proband had severe clinical symptoms and haplodose insufficiency which was the genetic etiology.

Objective:To investigate the clinical characteristics, genetic characteristics and diagnosis of spinocerebellar ataxia type 2 (SCA2) patients with childhood onset.Methods:The clinical data of a SCA2 pedigree who diagnosed at Neurogenetic Metabolic Disease Clinic of Children′s Hospital Affiliated to Zhengzhou University in July 2019 were collected, and the reported cases of childhood-onset SCA2 were reviewed. The CAG repeat of ATXN2 gene was detected by polymerase chain reaction, capillary gel electrophoresis and Sanger sequencing techniques.Results:A total of 9 people in 4 generations of the family were affected, showing an autosomal dominant inheritance. The proband was a 3 years and 4 months old boy, who showed abnormal symptoms at 9 months which manifested as developmental retardation. At 1 year old, he developed progressive regression which represented neither to be amused, recognize others, stand and walk alone, nor had language development. Meanwhile, he had difficulty swallowing, long-term constipation, and a history of convulsions. His sister and mother were not yet sick. His grandmother could not walk, had slurred speech accompanied by nystagmus, and magnetic resonance imaging showed cerebellar atrophy. His granduncles and grandaunts had unstable walking and dysarthria. His great-grandfather required wheelchair to walk. This pedigree showed an autosomal dominant inheritance. One of the ATXN2 gene alleles of the proband, his sister, mother and grandmother all showed abnormal amplification with 99, 55, 44, and 43 times respectively and no inserting CAA sequence. A total of 14 literatures reported 20 cases of childhood-onset SCA2 patients who were genetically diagnosed. The majorities had onset in infancy, and few can develop into school age. The main clinical manifestations were developmental delay, dystonia or insufficiency, myoclonus or infantile spasms, motor retardation, abnormal eye movement, retinitis pigmentosa and dysphagia, while the classic cerebellar syndrome was only partially present. Abnormal rhythm was found on electroencephalogram, cerebellar atrophy on magnetic resonance imaging or CT of the head.Conclusions:This case is the youngest genetically-confirmed SCA2 patient reported in China. Reported patients usually have onset in infancy with excessive repeat sequence expansion. Their clinical characteristics are different from the classic patients and could only be diagnosed by dynamic mutation detection.