Focal cortical dysplasia II caused by brain somatic mutation of IRS-1 is associated with ERK signaling pathway activation.

Somatic mutations have been identified in 10% to 63% of focal cortical dysplasia type II samples, primarily linked to the mTOR pathway. When the causative genetic mutations are not identified, this opens the possibility of discovering new pathogenic genes or pathways that could be contributing to the condition. In our previous study, we identified a novel candidate pathogenic somatic variant of IRS-1 c.1791dupG in the brain tissue of a child with focal cortical dysplasia type II. This study further explored the variant's role in causing type II focal cortical dysplasia through in vitro overexpression in 293T and SH-SY5Y cells and in vivo evaluation via in utero electroporation in fetal brains, assessing effects on neuronal migration, morphology, and network integrity. It was found that the mutant IRS-1 variant led to hyperactivity of p-ERK, increased cell volume, and was predominantly associated with the MAPK signaling pathway. In vivo, the IRS-1 c.1791dupG variant induced abnormal neuron migration, cytomegaly, and network hyperexcitability. Notably, the ERK inhibitor GDC-0994, rather than the mTOR inhibitor rapamycin, effectively rescued the neuronal defects. This study directly highlighted the ERK signaling pathway's role in the pathogenesis of focal cortical dysplasia II and provided a new therapeutic target for cases of focal cortical dysplasia II that are not treatable by rapamycin analogs.

Which terms should be used to describe medications used in the treatment of seizure disorders? An ILAE position paper.

A variety of terms, such as "antiepileptic," "anticonvulsant," and "antiseizure" have been historically applied to medications for the treatment of seizure disorders. Terminology is important because using terms that do not accurately reflect the action of specific treatments may result in a misunderstanding of their effects and inappropriate use. The present International League Against Epilepsy (ILAE) position paper used a Delphi approach to develop recommendations on English-language terminology applicable to pharmacological agents currently approved for treating seizure disorders. There was consensus that these medications should be collectively named "antiseizure medications". This term accurately reflects their primarily symptomatic effect against seizures and reduces the possibility of health care practitioners, patients, or caregivers having undue expectations or an incorrect understanding of the real action of these medications. The term "antiseizure" to describe these agents does not exclude the possibility of beneficial effects on the course of the disease and comorbidities that result from the downstream effects of seizures, whenever these beneficial effects can be explained solely by the suppression of seizure activity. It is acknowledged that other treatments, mostly under development, can exert direct favorable actions on the underlying disease or its progression, by having "antiepileptogenic" or "disease-modifying" effects. A more-refined terminology to describe precisely these actions needs to be developed.

Surgical treatment for drug-resistant epilepsy due to early brain injury in children.

BACKGROUND: The study aimed to summarize the indications and clinical features of pediatric drug-resistant epilepsy associated with early brain injury, surgical outcomes, and prognostic factors. METHODS: We retrospectively analyzed children diagnosed with drug-resistant epilepsy due to early brain injury, who had undergone surgery at the Pediatric Epilepsy Center of Peking University First Hospital from May 2014 to May 2021. Clinical data of vasculogenic and non-vasculogenic injuries from early brain damage were compared and analyzed. The surgical outcomes were assessed using the Engel grading system. RESULTS: The median ages at acquiring injury, seizure onset, and surgery among 65 children were 19.0 (0-120) days, 8.6 (0-136.5) months, and 62.9 (13.5-234) months, respectively. Of the 14 children with non-vasculogenic injuries, 12 had posterior ulegyria. Unilateral or bilateral synchronous interictal epileptiform discharges were located mainly in the posterior quadrant in 10 children (71 %), and unilateral posterior quadrant or non-lateralized ictal region in eight children (57 %). The surgical approach was mainly temporo-parieto-occipital or parieto-occipital disconnection in nine children. Of 49 children with vasculogenic injuries, magnetic resonance imaging revealed hemispheric abnormalities in 38. Unilaterally hemispheric or bilateral interictal epileptiform discharges were observed in 36 children (73 %), whereas 42 (86 %) had unilateral hemispheric or non-lateralized ictal onset. The surgical procedure involved hemispherotomy in 38 children (78 %) and lobectomy or disconnection, multilobectomy or disconnection and hemispherotomy in 5, 20, and 40 children, respectively. Fifty-five patients (84.6 %) achieved remission from seizure during follow-up at 5.4 years. Age at surgery (odds ratio = 1.022, 95 % confidence interval = 1.003-1.042, P = 0.023) and etiology (odds ratio = 17.25, 95 % confidence interval = 2.778-107.108, P = 0.002) affected the seizure outcomes. CONCLUSION: Children with drug-resistant epilepsy due to early brain injury can successfully be treated with surgery after rigorous preoperative screening. Good surgical outcomes are associated with an early age at surgery and an etiology of vasculogenic injury.

Impact of epilepsy surgery on developmental trajectories of children under 3 years of age.

AIM: To investigate the developmental effects of epilepsy surgery in young children. METHOD: This study retrospectively reviewed 315 consecutive children under 3 years of age, and ultimately included 89 children (48 males, 41 females) with pre- and postsurgery developmental evaluations. RESULTS: The mean general quotient before surgery was 46.7 (SD 24.7). Before surgery, the general quotient decreased in 77.6% of patients, while after surgery it increased in 55.1%. Furthermore, 70% of those 20 patients whose presurgical general quotient decreased by more than 10 points experienced positive changes. General quotient scores decreased in 15 out of the 22 patients classified in the normal/marginal presurgical category. Children who underwent surgery before the age of 12 months had a median gain in general quotient score by 7.6. Short-term general quotient scores were highly correlated with long-term scores (r = 0.909, p < 0.001). INTERPRETATION: Surgical intervention was more inclined to positively impact developmental trajectories within a short postsurgical period, particularly among those affected by severe epileptic activity. However, in children with relatively typical development, certain developmental setbacks may arise. Postsurgical short-term developmental outcomes could predict longer-term outcomes.

Clinical and functional consequences of GRIA variants in patients with neurological diseases.

AMPA receptors are members of the glutamate receptor family and mediate a fast component of excitatory synaptic transmission at virtually all central synapses. Thus, their functional characteristics are a critical determinant of brain function. We evaluate intolerance of each GRIA gene to genetic variation using 3DMTR and report here the functional consequences of 52 missense variants in GRIA1-4 identified in patients with various neurological disorders. These variants produce changes in agonist EC50, response time course, desensitization, and/or receptor surface expression. We predict that these functional and localization changes will have important consequences for circuit function, and therefore likely contribute to the patients' clinical phenotype. We evaluated the sensitivity of variant receptors to AMPAR-selective modulators including FDA-approved drugs to explore potential targeted therapeutic options.

Glomerular basement membrane ultrastructural changes in a patient with COQ2 glomerulopathy: A case report.

Primary coenzyme Q10 deficiency-1, caused by COQ2 disease-causing variants, is an autosomal recessive disorder, and genetic testing is the gold standard for diagnosing this condition. A Chinese boy with steroid-resistant nephrotic syndrome, focal segmental glomerulosclerosis, and progressive kidney insufficiency was included in the study. Electron microscopy revealed the glomerular basement membrane with irregular thickness and lamellation with diffuse effacement of foot processes in the podocytes, and swollen mitochondria with abnormal cristae in the podocytes. Coenzyme Q10 supplementation started about 3 weeks after the onset of mild kidney dysfunction did not improve the proband's kidney outcome. Proband-only whole-exome sequencing and Sanger sequencing revealed two heteroallelic COQ2 variants: a maternally inherited novel variant c.1013G > A[p.(Gly338Glu)] in exon 6 and a variant of unknown origin c.1159C > T[p.(Arg387*)] in exon 7. Subsequent long-read sequencing demonstrated these two variants were located on different alleles. Our report extends the phenotypic and genotypic spectrum of COQ2 glomerulopathy.

[Different concentrations of adapalene induce differentiation and apoptosis of SH-SY5Y cells]. / 不同浓度阿达帕林诱导SH-SY5Y细胞的分化及凋亡.

OBJECTIVES: To investigate the effects of different concentrations of adapalene on the morphology and functions of neuroblastoma cell line SH-SY5Y, as well as its role in inducing cell differentiation and apoptosis. METHODS: SH-SY5Y cells were divided into control group, low concentration (0.1 µM and 1 µM) adapalene groups, and high concentration (10 µM) adapalene group. Time-lapse microscopy was used to observe the morphological changes of SH-SY5Y cells. Immunofluorescence staining was performed to detect the expression of neuronal specific marker ßIII-tubulin and mature neuronal marker neurofilament heavy polypeptide (NFH). Multi-electrode array was used to record the electrophysiological features of SH-SY5Y cells. Cell apoptosis was evaluated using a cell apoptosis detection kit. RESULTS: Low concentrations of adapalene promoted the formation of neurite outgrowth in SH-SY5Y cells, with the neurites interconnected to form a network. Spontaneous discharge activity was observed in SH-SY5Y cells treated with low concentrations of adapalene. Compared to the control group, the expression of ßIII-tubulin and NFH increased in the 1 µM adapalene group, while the level of cell apoptosis increased in the high concentration adapalene group (P<0.05). CONCLUSIONS: Low concentrations of adapalene can induce differentiation of SH-SY5Y cells into mature functional neurons, while high concentrations of adapalene can induce apoptosis in SH-SY5Y cells.

CAG Repeat Expansion in THAP11 Is Associated with a Novel Spinocerebellar Ataxia.

BACKGROUND: More than 50 loci are associated with spinocerebellar ataxia (SCA), and the most frequent subtypes share nucleotide repeats expansion, especially CAG expansion. OBJECTIVE: The objective of this study was to confirm a novel SCA subtype caused by CAG expansion. METHODS: We performed long-read whole-genome sequencing combined with linkage analysis in a five-generation Chinese family, and the finding was validated in another pedigree. The three-dimensional structure and function of THAP11 mutant protein were predicted. Polyglutamine (polyQ) toxicity of THAP11 gene with CAG expansion was assessed in skin fibroblasts of patients, human embryonic kidney 293 and Neuro-2a cells. RESULTS: We identified THAP11 as the novel causative SCA gene with CAG repeats ranging from 45 to 100 in patients with ataxia and from 20 to 38 in healthy control subjects. Among the patients, the number of CAA interruptions within CAG repeats was decreased to 3 (up to 5-6 in controls), whereas the number of 3' pure CAG repeats was up to 32 to 87 (4-16 in controls), suggesting that the toxicity of polyQ protein was length dependent on the pure CAG repeats. Intracellular aggregates were observed in cultured skin fibroblasts from patients. THAP11 polyQ protein was more intensely distributed in the cytoplasm of cultured skin fibroblasts from patients, which was replicated with in vitro cultured neuro-2a transfected with 54 or 100 CAG repeats. CONCLUSIONS: This study identified a novel SCA subtype caused by intragenic CAG repeat expansion in THAP11 with intracellular aggregation of THAP11 polyQ protein. Our findings extended the spectrum of polyQ diseases and offered a new perspective in understanding polyQ-mediated toxic aggregation. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

De novo CLPTM1 variants with reduced GABAA R current response in patients with epilepsy.

OBJECTIVE: To investigate the clinical features and potential pathogenesis mechanism of de novo CLPTM1 variants associated with epilepsy. METHODS: Identify de novo genetic variants associated with epilepsy by reanalyzing trio-based whole-exome sequencing data. We analyzed the clinical characteristics of patients with these variants and performed functional in vitro studies in cells expressing mutant complementary DNA for these variants using whole-cell voltage-clamp current recordings and outside-out patch-clamp recordings from transiently transfected human embryonic kidney (HEK) cells. RESULTS: Two de novo missense variants related to epilepsy were identified in the CLPTM1 gene. Functional studies indicated that CLPTM1-p.R454H and CLPTM1-p.R568Q variants reduced the γ-aminobutyric acid A receptor (GABAA R) current response amplitude recorded under voltage clamp compared to the wild-type receptors. These variants also reduced the charge transfer and altered the time course of desensitization and deactivation following rapid removal of GABA. The surface expression of the GABAA R γ2 subunit from the CLPTM1-p.R568Q group was significantly reduced compared to CLPTM1-WT. SIGNIFICANCE: This is the first report of functionally relevant variants within the CLPTM1 gene. Patch-clamp recordings showed that these de novo CLPTM1 variants reduce GABAA R currents and charge transfer, which should promote excitation and hypersynchronous activity. This study may provide insights into the molecular mechanisms of the CLPTM1 variants underlying the patients' phenotypes, as well as for exploring potential therapeutic targets for epilepsy.

In Vitro Effects of Acitretin on Human Neuronal SH-SY5Y Cells.

Acitretin is an oral drug approved by the Food and Drug Administration that is commonly used to treat psoriasis. In recent years, acitretin has been identified as a candidate drug for the treatment of Alzheimer's disease, but its role in neuronal development is still unclear. In this study, the human neuroblastoma cell line SH-SY5Y was used as a model to study neuronal differentiation. We found that acitretin effectively promoted the differentiation of SH-SY5Y cells into neuronal cells and upregulated the expression of the neuronal marker ß-III tubulin and the mature neuronal marker NFH. Differentially expressed genes were identified by RNA sequencing and analyzed by bioinformatics approaches. The results showed that genes associated with neuron development-related pathways, such as SSPO and KCNT1, had significant changes in expression. Analysis showed that PRKCA and CAMK2B may play important roles in the process by which acitretin promotes neurodevelopment. Through whole-cell patch clamping and a microelectrode array assay, we found that acitretin-treated neurons generated electrical spikes similar to those generated by mature neurons. This study provided evidence to support an accessible and safe model of neuron-like cells and verified that acitretin can promote the differentiation of neurons and has the potential to treat brain tumors and neurodevelopmental and neurodegenerative diseases.

Seizure course of PCDH19 clustering epilepsy in female children: A multicentre cohort study in China.

AIM: To investigate the seizure course of PCDH19 clustering epilepsy (PCDH19-CE) in a cohort of female children in China. METHOD: This ambidirectional cohort study examined 113 female patients with PCDH19-CE through multicentre collaboration. Prognostic factors for seizure freedom were evaluated by multivariate Cox regression analysis. RESULTS: The median seizure course period from seizure onset was 6 years 6 months. Of 113 patients, 78% and 56% experienced seizure freedom for at least 1 year and at least 2 years respectively. In patients younger than 5 years (n = 30), 5 to 10 years (n = 52), and older than 10 years (n = 31), 57%, 81%, and 94% experienced at least 1 year of seizure freedom, and 32%, 52%, and 84% experienced at least 2 years of seizure freedom, respectively. However, 58% (65 out of 113) relapsed at least once after more than 1 year of seizure freedom without trigger exposure (40%) or because of common triggers, including fever (43%) and antiseizure medication (ASM) reduction (29%). There was an 84% risk of seizure relapse after ASM reduction attempts. The likelihood of seizure freedom decreased with early age at seizure onset and developmental delay. INTERPRETATION: Patients with PCDH19-CE exhibit increasing seizure freedom with age, but there is a risk of relapse. ASM reduction in children younger than 10 years old requires caution. Patients with early seizure onset and developmental delay have a reduced chance of seizure freedom.

Heterozygous Variants in the Mechanosensitive Ion Channel TMEM63A Result in Transient Hypomyelination during Infancy.

Mechanically activated (MA) ion channels convert physical forces into electrical signals. Despite the importance of this function, the involvement of mechanosensitive ion channels in human disease is poorly understood. Here we report heterozygous missense mutations in the gene encoding the MA ion channel TMEM63A that result in an infantile disorder resembling a hypomyelinating leukodystrophy. Four unrelated individuals presented with congenital nystagmus, motor delay, and deficient myelination on serial scans in infancy, prompting the diagnosis of Pelizaeus-Merzbacher (like) disease. Genomic sequencing revealed that all four individuals carry heterozygous missense variants in the pore-forming domain of TMEM63A. These variants were confirmed to have arisen de novo in three of the four individuals. While the physiological role of TMEM63A is incompletely understood, it is highly expressed in oligodendrocytes and it has recently been shown to be a MA ion channel. Using patch clamp electrophysiology, we demonstrated that each of the modeled variants result in strongly attenuated stretch-activated currents when expressed in naive cells. Unexpectedly, the clinical evolution of all four individuals has been surprisingly favorable, with substantial improvements in neurological signs and developmental progression. In the three individuals with follow-up scans after 4 years of age, the myelin deficit had almost completely resolved. Our results suggest a previously unappreciated role for mechanosensitive ion channels in myelin development.

A phase 2, randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of soticlestat as adjunctive therapy in pediatric patients with Dravet syndrome or Lennox-Gastaut syndrome (ELEKTRA).

OBJECTIVE: Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS) are rare treatment-resistant childhood epilepsies classed as developmental and epileptic encephalopathies. ELEKTRA investigated the efficacy and safety of soticlestat (TAK-935) as adjunctive therapy in children with DS or LGS (NCT03650452). METHODS: ELEKTRA was a phase 2, randomized, double-blind, placebo-controlled study of soticlestat (≤300 mg twice daily, weight-adjusted) in children (aged 2-17 years) with DS, demonstrating three or more convulsive seizures/month, or with LGS, demonstrating four or more drop seizures/month at baseline. The 20-week treatment period comprised an 8-week dose-optimization period and a 12-week maintenance period. Efficacy endpoints included change from baseline in seizure frequency versus placebo. Safety assessments included incidence of treatment-emergent adverse events (TEAEs). RESULTS: ELEKTRA enrolled 141 participants; 126 (89%) completed the study. The modified intent-to-treat population included 139 participants who received one or more doses of study drug and had one or more efficacy assessments (DS, n = 51; LGS, n = 88). ELEKTRA achieved its primary endpoint: the combined soticlestat-treated population demonstrated a placebo-adjusted median reduction in seizure frequency of 30.21% during the maintenance period (p = .0008, n = 139). During this period, placebo-adjusted median reductions in convulsive and drop seizure frequencies of 50.00% (p = .0002; patients with DS) and 17.08% (p = .1160; patients with LGS), respectively, were observed. TEAE incidences were similar between the soticlestat (80.3%) and placebo (74.3%) groups and were mostly mild or moderate in severity. Serious TEAEs were reported by 15.5% and 18.6% of participants receiving soticlestat and placebo, respectively. TEAEs reported in soticlestat-treated patients with ≥5% difference from placebo were lethargy and constipation. No deaths were reported. SIGNIFICANCE: Soticlestat treatment resulted in statistically significant, clinically meaningful reductions from baseline in median seizure frequency (combined patient population) and in convulsive seizure frequency (DS cohort). Drop seizure frequency showed a nonstatistically significant numerical reduction in children with LGS. Soticlestat had a safety profile consistent with previous studies.

Transcriptome Analysis Reveals the Anti-Tumor Mechanism of Eucalyptol Treatment on Neuroblastoma Cell Line SH-SY5Y.

Eucalyptol (1.8-cineole), an active component in traditional Chinese medicine Artemisia argyi for moxibustion. Previous studies have shown that eucalyptol has anti-tumor effects on leukemia and colon cancer. Nonetheless, the effect and mechanism of eucalyptol on neuroblastoma remains unclear. In the present study, we intended to reveal the effect and mechanism of eucalyptol treatment on the neuroblastoma cell line SH-SY5Y through transcriptome analysis. In the group treated with eucalyptol, 566 brain genes were up-regulated, while 757 genes were down-regulated. GO function analysis showed that positive regulation of cell cycle was down-regulated in biological processes. Meanwhile, cancer-related pathways were identified in KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis, including pathways in cancer, PI3K-Akt signaling pathway, cAMP signaling pathway, TGF-beta signaling pathway, Hippo signaling pathway, p53 signaling pathway, and additional pathways. Furthermore, we found a key gene, such as MYC, by constructing a network of cancer related pathways with differentially expressed genes and transcription factor analysis. In conclusion, our research indicates that MYC might play a central role in the anit-tumor mechanisms of eucalyptol.

Secretomics Alterations and Astrocyte Dysfunction in Human iPSC of Leukoencephalopathy with Vanishing White Matter.

Leukoencephalopathy with vanishing white matter (VWM) is an inherited leukoencephalopathy characterized by progressive rarefaction of cerebral white matter. Dysfunction of patient astrocyte plays a central role in the pathogenesis, while the immaturity of oligodendrocyte is probably secondary. How eIF2B mutant astrocytes affect the maturation and myelination of oligodendrocyte precursor cells (OPCs) is unclear yet. We used induced pluripotent stem cells (iPSCs) derived from our patient with EIF2B5 mutations to differentiate into astrocytes (AS) and OPCs, and aimed to verify that patient astrocytes inhibited the differentiation of OPCs by abnormalities of secreted proteins. eIF2B mutant astrocytes and astrocyte-conditioned medium (ACM) both inhibited the maturation of OPCs. It was revealed that 13 promising proteins exhibited a similar up- or downregulation by the PRM method correlated well with TMT results. eIF2B mutant astrocytes may secrete abnormal extracellular matrix (HA, LAMA4, BGN, FBN1, VASN, PCOLCE, MFAP4), cytokines (IL-6, CRABP1, ISG15), growth factors (PDGF-AA, CNTF, IGF-II, sFRP1, SERPINF1) and increased FABP7, which might lead to the differentiation and maturation disorder of OPCs. We analyzed the astrocyte-conditioned medium to find the key secretory molecules affecting the differentiation and maturation of OPCs, which provides potential clues for further research on the mechanism of VWM.

Neuroblastoma SH-SY5Y Cell Differentiation to Mature Neuron by AM580 Treatment.

Neuroblastoma is a type of developmental childhood cancer that arises from the neural crest. It is the most common pediatric solid tumor in the world. AM580 is a powerful cyto-differentiating molecule on acute promyelocytic leukemia cells and induced pluripotent stem cells, but its effect on neuroblastoma is still unknown. In this study, the neuronal differentiation impact of AM580 was investigated using the human neuroblastoma cell line SH-SY5Y as a model. AM580 successfully stimulated the SH-SY5Y cells to develop into neuron-like cells. Functional enrichment analysis of RNAseq data revealed that differentially expressed genes (DEGs) were substantially enriched for GO keywords and KEGG pathways linked to neuron development. Some potassium ion channel genes associated with neuronal excitation, such as KCNT1, were shown to be upregulated. Through the MEA tests, we found the AM580-induced neurons possessed electrical spikes as mature neurons. AM580 also induced the neuronal marker ß-tubulin III and mature neurons marker Neurofilament H. Our study proved that AM580 can promote the differentiation of neurons and has the potential to treat neuroblastoma, neurodevelopmental and neurodegenerative diseases.

Potassium channels and epilepsy.

With the development and application of next-generation sequencing technology, the aetiological diagnosis of genetic epilepsy is rapidly becoming easier and less expensive. Additionally, there is a growing body of research into precision therapy based on genetic diagnosis. The numerous genes in the potassium ion channel family constitute the largest family of ion channels: this family is divided into different subtypes. Potassium ion channels play a crucial role in the electrical activity of neurons and are directly involved in the mechanism of epileptic seizures. In China, scientific research on genetic diagnosis and studies of precision therapy for genetic epilepsy are progressing rapidly. Many cases of epilepsy caused by mutation of potassium channel genes have been identified, and several potassium channel gene targets and drug candidates have been discovered. The purpose of this review is to briefly summarize the progress of research on the precise diagnosis and treatment of potassium ion channel-related genetic epilepsy, especially the research conducted in China. Here in, we review several large cohort studies on the genetic diagnosis of epilepsy in China in recent years, summarized the proportion of potassium channel genes. We focus on the progress of precison therapy on some hot epilepsy related potassium channel genes: KCNA1, KCNA2, KCNB1, KCNC1, KCND2, KCNQ2, KCNQ3, KCNMA1, and KCNT1.

Genotype-phenotype correlation of CACNA1A variants in children with epilepsy.

AIM: To explore the genotypes and phenotypes of CACNA1A variants in children with epilepsy. METHOD: Eighteen children (six males, 12 females) with CACNA1A variants were identified using next-generation sequencing. RESULTS: There were 14 missense variants, two nonsense variants, one frameshift variant, and one splice site variant. Sixteen variants were de novo. Age at seizure onset ranged from 1 day to 8 years; median age was 8 months. Multiple seizure types were observed, including focal, generalized tonic-clonic, myoclonic, and absence seizures, as well as epileptic spasms and tonic seizures. Focal motor status epilepticus occurred in 10 individuals and generalized motor status epilepticus occurred in two individuals. All 18 children showed developmental delay. Focal motor status epilepticus resulted in cerebral atrophy in five individuals, mainly on the contralateral side. Interictal electroencephalogram showed focal discharges in 12 individuals, whereas five individuals had generalized discharges. Three individuals were seizure-free, whereas 15 still had seizures and five had recurrent status epilepticus at last follow-up. INTERPRETATION: Most children with epilepsy and CACNA1A variants had early seizure onset and developmental delay. Focal seizure was the most common seizure type. Most patients experienced status epilepticus. Unilateral cerebral atrophy could occur after focal motor status epilepticus. Patients with CACNA1A variants located in the transmembrane region may be at high risk of status epilepticus.

[Factors affecting phenotypes in the patients with MMACHC gene c.609G>A homozygous variant cblC type methylmalonic acidemia combined with homocysteinuria].

OBJECTIVE: To investigate the factors affecting phenotypes in the patients of methylmalonic acidemia combined with homocysteinemia cblC type with MMACHC c.609G>A homologous variant. METHODS: A retrospective study on the clinical manifestations, complications, treatment, and outcome in 164 patients of cblC type with MMACHC c.609G>A homologous variant was conducted. The patients were diagnosed by biochemical and genetic analysis from January 1998 to December 2020. RESULTS: Among the 164 patients, 2 cases were prenatally diagnosed and began treatment after birth. They are 3 and 12 years old with normal physical and mental development. Twenty-one cases were diagnosed by newborn screening. Among them, 15 cases had with normal development. They were treated from the age of two weeks at the asymptomatic period. Six cases began treatment aged 1 to 3 months after onset. Their development was delayed. One hundred and forty-one cases were clinically diagnosed. Their onset age ranges from a few minutes after birth to 6 years old. 110 cases had early-onset (78.0%). 31 cases had late-onset (22.0%). Five of them died. 24 patients lost to follow-up. Of the 141 clinically diagnosed patients, 130 (92.2%) with psychomotor retardation, 69 (48.9%) with epilepsy, 39 (27.7%) with anemia, 30 (21.3%) had visual impairment, 27 (19.1%) had hydrocephalus, 26 (18.4%) had feeding difficulties, 7 (5.0%) with liver damage, and 5 (3.5%) with metabolic syndrome. The frequency of hydrocephalus and seizures was significantly higher in the early-onset group. The urinary methylmalonic acid increased significantly in the patients with epilepsy. During the long-term follow-up, the level of plasma total homocysteine in the seizure-uncontrolled group was significantly higher than that in the seizure-controlled group, the difference had a statistical significance (P<0.05). CONCLUSION: Most of the patients with MMACHC c.609G>A homozygous variant had early-onset disease, with a high mortality and disability rate. If not treated in time, it will lead to neurological damage, resulting in epilepsy, mental retardation, hydrocephalus, and multiple organ damage. Pre-symptomatic diagnosis and treatment are crucial to prevent irreversible neurological damage. Neonatal screening and prenatal diagnosis are important to improve the outcome of the patients.

De Novo Mutations of CCNK Cause a Syndromic Neurodevelopmental Disorder with Distinctive Facial Dysmorphism.

Neurodevelopment is a transcriptionally orchestrated process. Cyclin K, a regulator of transcription encoded by CCNK, is thought to play a critical role in the RNA polymerase II-mediated activities. However, dysfunction of CCNK has not been linked to genetic disorders. In this study, we identified three unrelated individuals harboring de novo heterozygous copy number loss of CCNK in an overlapping 14q32.3 region and one individual harboring a de novo nonsynonymous variant c.331A>G (p.Lys111Glu) in CCNK. These four individuals, though from different ethnic backgrounds, shared a common phenotype of developmental delay and intellectual disability (DD/ID), language defects, and distinctive facial dysmorphism including high hairline, hypertelorism, thin eyebrows, dysmorphic ears, broad nasal bridge and tip, and narrow jaw. Functional assay in zebrafish larvae showed that Ccnk knockdown resulted in defective brain development, small eyes, and curly spinal cord. These defects were partially rescued by wild-type mRNA coding CCNK but not the mRNA with the identified likely pathogenic variant c.331A>G, supporting a causal role of CCNK variants in neurodevelopmental disorders. Taken together, we reported a syndromic neurodevelopmental disorder with DD/ID and facial characteristics caused by CCNK variations, possibly through a mechanism of haploinsufficiency.