Aristaless-related Homeobox Research Articles

Synaptic and membrane properties of cholinergic interneurons in the striatum of aristaless-related homeobox gene mutant mice.

A whole-cell patch-clamp study was carried out to investigate membrane and synaptic properties of cholinergic interneurons in the striatum of aristaless-related homeobox gene (ARX) mutant mice. Brain slices were prepared from mice knocked in two types of ARX, P355L (PL) and 333ins (GCG)7 (GCG). The input resistance of cholinergic interneurons in PL or GCG mice was significantly smaller than that in wild type (WT), whereas resting membrane potential, threshold of action potentials, spontaneous firing rate, sag ratio or afterhyperpolarization of the mutant mice were not significantly different from those of WT mice. In GCG mice, NMDA/AMPA ratio of excitatory postsynaptic currents (EPSCs) evoked in cholinergic interneurons was significantly smaller than that in WT and PL mice, whereas the ratio between PL and WT mice was not significantly different. Although inhibitory effects induced by dopamine D2-like receptor activation on the inhibitory postsynaptic currents (IPSCs) were not significantly different between WT and PL or GCG mice, increase in the paired pulse ratio of IPSCs by dopamine D2-like receptor activation was abolished in PL and GCG mice. The present results have found abnormalities of neuronal activities as well as its modulation in the basal ganglia in ARX mutant mice, clarifying basic mechanisms underlying related disorders.

ARX regulates cortical interneuron differentiation and migration.

Mutations in aristaless-related homeobox ( ARX ) are associated with neurodevelopmental disorders including developmental epilepsies, intellectual disabilities, and autism spectrum disorders, with or without brain malformations. Aspects of these disorders have been linked to abnormal cortical interneuron (cIN) development and function. To further understand ARX's role in cIN development, multiple Arx mutant mouse lines were interrogated. We found that ARX is critical for controlling cIN numbers and distribution, especially, in the developing marginal zone (MZ). Single cell transcriptomics and ChIP-seq, combined with functional studies, revealed ARX directly or indirectly regulates genes involved in proliferation and the cell cycle (e.g., Bub3 , Cspr3 ), fate specification (e.g., Nkx2.1 , Maf , Mef2c ), and migration (e.g., Nkx2.1 , Lmo1 , Cxcr4 , Nrg1 , ErbB4 ). Our data suggest that the MZ stream defects primarily result from disordered cell-cell communication. Together our findings provide new insights into the mechanisms underlying cIN development and migration and how they are disrupted in several disorders.

#489 UCP1 regulates cardiolipin metabolism and mediates mitochondrial homeostasis maintenance of ANXA1 in diabetic nephropathy

Abstract Background and Aims Diabetic nephropathy (DN) is accounted for a large proportion of chronic kidney disease (CKD) and is the leading cause of end-stage renal disease (ESRD) nowadays. The complex pathogenesis of DN has hindered the development of a single effective medicine, so it is of great significance to seek new therapeutic targets. Uncoupling of mitochondrial respiration by chemical uncouplers has proven effective in ameliorating obesity, insulin resistance, and hyperglycemia, which were risk factors for DN. Recently, we found that ANXA1 could improve mitochondrial function to mitigate DN progression. However, the underlying mechanism is not fully clear yet. Method We used kidney samples from patients in our hospital. ANXA1-KO mice with local renal overexpression of UCP1 were constructed, UCP1-KO mice were constructed for STZ/HFD modeling, and db/db mice were treated with CL316243. UCP1-KO mice with renal overexpression of CRLS1 were constructed. Mice with PTECs-specific deletion of ANXA1 were constructed. Cell lines with UCP1/ANXA1/GATA3 knockdown and UCP1/ANXA1/GATA3 overexpression were constructed, and cell reversal tests were performed using Ac2-26, CL316243 and siRNA targeting the above genes. Results Here, we identified uncoupling protein 1 (UCP1), an inner membrane protein of mitochondria, as a key to mitochondrial homeostasis improved by ANXA1. Specifically, ANXA1 attenuated mitochondrial dysfunction via appropriately upregulating UCP1 by stabilizing its transcription factor GATA binding protein 3 (GATA3) through combining with thioredoxin. Moreover, specific overexpression of UCP1 in renal cortex rescued renal injuries in diabetic Anxa1-KO mice. UCP1 deletion aggravated renal injuries in HFD/STZ-induced diabetic mice. Mechanistically, UCP1 reduced mitochondrial fission through the aristaless-related homeobox (ARX)/cardiolipin synthase 1 (CRLS1) pathway. Therapeutically, CL316243, a UCP1 agonist, could attenuate established DN in db/db mice. Conclusion Thus, our data unraveled specific mechanism by which UCP1 mediated mitochondrial homeostasis maintenance via the ANXA1-GATA3-UCP1-ARX-CRLS1 signaling pathway. This work established a novel principle to harness the power of uncouplers for the treatment of DN.

Clinical Case of Rare Genetic Disorder (Proud Syndrome) in a Child

Background. Proud syndrome is rare inherited disease with X-linked inheritance associated with mutations in the homeobox gene ARX. Typical clinical signs of this syndrome are severe mental retardation, intractable epilepsy, agenesis (dysgenesis) of corpus callosum. Less common features are genital abnormalities, microcephaly, facial dysmorphia, and skeletal malformations. Clinical case description. The article describes the clinical findings of Proud syndrome in girl A., admitted to Children’s City Clinical Hospital No. 1 in Nizhny Novgorod. The girl was born without asphyxia at term through natural vaginal delivery after the first uneventful pregnancy. Body weight at birth was 2600 g. The genealogical history is burdened by the presence of epilepsy in girl’s father relatives. There were no deviations in psychomotor skills development before disease onset. Hemi-convulsive seizures (switching sides) have appeared at the age of 6 months. These attacks had status course and were resistant to anticonvulsant therapy. Neuroimaging has revealed agenesis of corpus callosum. Regression of psychomotor development, new behavioral disorders (stereotypes and auto-aggression), hyperexcitability, and sleep disorders were observed in dynamics. The diagnosis of Proud syndrome was confirmed by identification of probably pathogenic mutation in the ARX gene (c.1111C>T, p. Arg 371*64). The features of anticonvulsant management were demonstrated in the patient. Conclusion. This clinical case presents typical clinical picture of Proud syndrome. The disease is non-curable. Such patients should be administered with syndromic therapy: constant anticonvulsant therapy, correction of behavioral disorders (classes with specialist on mental defects), neurologist, epileptologist, psychiatrist observations. Parental examination is crucial ARX mutation search in order to determine the prognosis for further child-bearing (parents refused to perform genetic study at the time of article writing).

Lissencephaly, Pachygyrias, Band Heterotopias, RELN Pathway, and ARX Mutations (Incomplete Neuron Migration)

AbstractLissencephaly (LIS) is a group of malformations of cortical development consisting of a defective neuronal migration that results in lack of formation of the normal cerebral convolutions. It includes a spectrum of defect with varying degrees of severity, from agyria and pachygyria to subcortical band heterotopia. The etiopathogenesis of LIS includes both genetic and environmental factors. Although nongenetic forms of LIS have been reported, genetic causes are certainly more frequent and to date 19 LIS-SBH-associated genes have been identified. Most common mutations involve LIS1, DCX, ARX, and RELN genes. Clinically affected individuals present with early hypotonia, which can progress to limb spasticity, seizures, and psychomotor retardation. Convulsive episodes usually appear early (first months of life) and include infantile spasms, akinetic or myoclonic seizures, up to the development of complex epileptic syndromes, including atypical absences, myoclonia, and partial or tonic–clonic seizures. Several clinical entities are associated with classical LIS, including the following: isolated lissencephaly sequence (ILS); Miller–Dieker syndrome (MDS; OMIM 247200); subcortical band heterotopia (OMIM 300067); X-linked LIS with abnormal genitalia; and LIS with cerebellar hypoplasia. Diagnosis primarily depends on genetic and neuroimaging. Magnetic resonance imaging (MRI) is the gold standard, and it detects the presence of thick cortical cortex, its location, and the layers' architecture. Based on neuroimaging, it is possible to distinguish six subtypes of gyral malformations. Clinical and therapeutic management of these patients is challenging, considering the necessity to face drug-resistant epilepsy, intellectual disability, spasticity, and dysphagia and feeding problems. At the present moment, no gene-specific treatment for LIS is available.

Type 1 early infantile epileptic encephalopathy: A case report and literature review.

Variants in the Aristaless-related homeobox (ARX) gene lead to a variety of phenotypes, with intellectual disability being a steady feature. Other features can include severe epilepsy, spasticity, movement disorders, hydranencephaly, and ambiguous genitalia in males. X-linked Ohtahara syndrome or Type 1 early infantile epileptic encephalopathy (EIEE1) is a severe early-onset epileptic encephalopathy with arrested psychomotor development caused by hemizygous mutations in the ARX gene, which encodes a transcription factor in fundamental brain developmental processes. We presented a case report of a 2-year-old boy who exhibited symptoms such as microcephaly, seizures, and severe multifocal epileptic abnormalities, and genetic techniques such as autozygosity mapping, Sanger sequencing, and whole-exome sequencing. We confirmed that the patient had the NM_139058.3:c.84C>A; p.(Cys28Ter) mutation in the ARX gene. The patient with EIEE1 had physical symptoms and hypsarrhythmia on electroencephalogram. Genetic testing identified a causative mutation in the ARX gene, emphasizing the role of genetic testing in EIEE diagnosis.

The effects of EGCG supplementation on pancreatic islet α and β cells distribution in adult male mice

Tea and tea products are widely used as the most popular beverage in the world. EGCG is the most abundant bioactive tea polyphenol in green tea, which has positive effects on the prevention and treatment of diabetes. However, the impact of EGCG exposure on glucose homeostasis and islets in adult mice have not been reported. In this study, we studied glucose homeostasis and the morphological and molecular changes of pancreatic islet α and β cells in adult male mice after 60 d of exposure to 1 and 10 mg/kg/day EGCG by drinking water. Glucose homeostasis was not affected in both EGCG groups. The expression of pancreatic duodenal homebox1 (Pdx1) in β cells was upregulated, which might be related to increased insulin level, β cell mass and β cell proliferation in 10 mg/kg/day EGCG group. The expression of aristaless-related homeobox (Arx) in α cells did not change significantly, which corresponded with the unchanged α-cell mass. The significant reduction of musculoaponeurotic fibrosarcoma oncogene homolog B (MafB) positive α-cells might be associated with decreased glucagon level in both EGCG groups. These results suggest that EGCG supplementation dose-dependent increases β cell mass of adult mice and affects the levels of serum insulin and glucagon. Our results show that regular tea drinking in healthy people may have the possibility of preventing diabetes.

Arsenic resistance and accumulation by two bacteria isolated from Ratanpur Village of Varanasi District, Uttar Pradesh

Arsenic-resistant bacteria were isolated from Ratanpur Village of Varanasi District, Uttar Pradesh, by enrichment technique. The isolates, Proteus alimentorum strain TY6 and Pseudomonas aeruginosa strain K7Pb, showed high resistance to As(V) with minimum inhibitory concentration of 610 mM and 350 mM, respectively, and for As(III), 10 mM and 8 mM, respectively. TY6 could remove 96 ± 0.816 % As(V) and 66 ± 0.471 % As(III), whereas K7Pb could remove 98 ± 0.942 % As(V) and 78 ± 1.247 % As(III). Biotransformation ability was determined using AgNO3 and KMnO4 tests. PCR amplification showed the presence of aio, arr, arx and ars genes. Strains also showed resistance against other heavy metals such as Cd, Cr, Co, Pb, Hg, and Ni. Phytotoxicity assessment on chickpea and Vigna radiata (mung bean) revealed that the arsenic-contaminated water treated with the isolates can be used for irrigation purposes. It is also the first report of arsenic remediation by Proteus alimentorum bacteria (to the best of the authors' knowledge).

Analysis of ARX gene variant in a child with X-linked lissencephaly with abnormal genitalia

To explore the clinical characteristics and genetic basis for a child with X-linked lissencephaly with abnormal genitalia (XLAG). A child with XLAG who had presented at the Third Affiliated Hospital of Zhengzhou University in May 2021 was selected as the study subject. Peripheral blood samples of the child and his parents were collected and subjected to high-throughput sequencing. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the result was analyzed by using bioinformatic software. The child was found to have harbored a hemizygous c.945_948del variant in exon 2 of the ARX gene, which as a frameshifting variant has resulted in a truncated protein. His mother was found to be heterozygous for the variant, whilst his father was of wild type. The variant was unreported previously. The hemizygous c.945_948del variant of the ARX gene probably underlay the XLAG in this patient. Above finding has provided a basis for the diagnosis and genetic counseling for this family.

Pancreatic islet remodeling in cotadutide-treated obese mice

Obesity and type 2 diabetes mellitus (T2DM) cause morphofunctional alterations in pancreatic islet alpha and beta cells. Therefore, we hypothesize that the new GLP-1/Glucagon receptor dual agonist cotadutide may benefit islet cell arrangement and function. Twelve-week-old C57BL/6 male mice were fed a control diet (C, 10 % kJ fat) or a high-fat diet (HF, 50 % kJ fat) for ten weeks. Then, the animals were divided into four groups for an additional 30 days and daily treated with subcutaneous cotadutide (30 nmol/kg) or vehicle: C, CC (control+cotadutide), HF, and HFC (high-fat+cotadutide). Cotadutide led to weight loss and reduced insulin resistance in the HFC group, increasing insulin receptor substrate 1 and solute carrier family 2 gene expressions in isolated islets. Also, cotadutide enhanced transcriptional factors related to islet cell transdifferentiation, decreasing aristaless-related homeobox and increasing the paired box 4 and 6, pancreatic and duodenal homeobox 1, v-maf musculoaponeurotic fibrosarcoma oncogene family protein A, neurogenin 3, and neurogenic differentiation 1. In addition, cotadutide improved the proliferating cell nuclear antigen, NK6 homeobox 1, B cell leukemia/lymphoma 2, but lessening caspase 3. Furthermore, cotadutide mitigated the endoplasmic reticulum (ER) stress-responsive genes, reducing transcription factor 4, DNA-damage-inducible transcript 3, and growth arrest and DNA-damage-inducible 45. In conclusion, our data demonstrated significant beneficial actions of cotadutide in DIO mice, such as weight loss, glycemic control, and insulin resistance improvement. In addition, cotadutide counteracted the pathological adaptive cellular arrangement of the pancreatic islet in obese mice, improving the markers of the transdifferentiating pathway, proliferation, apoptosis, and ER stress.

EpiCRISPR targeted methylation of Arx gene initiates transient switch of mouse pancreatic alpha to insulin-producing cells.

Beta cell dysfunction by loss of beta cell identity, dedifferentiation, and the presence of polyhormonal cells are main characteristics of diabetes. The straightforward strategy for curing diabetes implies reestablishment of pancreatic beta cell function by beta cell replacement therapy. Aristaless-related homeobox (Arx) gene encodes protein which plays an important role in the development of pancreatic alpha cells and is a main target for changing alpha cell identity. In this study we used CRISPR/dCas9-based epigenetic tools for targeted hypermethylation of Arx gene promoter and its subsequent suppression in mouse pancreatic αTC1-6 cell line. Bisulfite sequencing and methylation profiling revealed that the dCas9-Dnmt3a3L-KRAB single chain fusion constructs (EpiCRISPR) was the most efficient. Epigenetic silencing of Arx expression was accompanied by an increase in transcription of the insulin gene (Ins2) mRNA on 5th and 7th post-transfection day, quantified by both RT-qPCR and RNA-seq. Insulin production and secretion was determined by immunocytochemistry and ELISA assay, respectively. Eventually, we were able to induce switch of approximately 1% of transiently transfected cells which were able to produce 35% more insulin than Mock transfected alpha cells. In conclusion, we successfully triggered a direct, transient switch of pancreatic alpha to insulin-producing cells opening a future research on promising therapeutic avenue for diabetes management.

Comment on: Are Parenchyma-Sparing Resections Really Appropriate for Small (

Comment on: Are Parenchyma-Sparing Resections Really Appropriate for Small (<3 cm) Nonfunctional Pancreatic Neuroendocrine Tumors?

Phenotypes of a female patient with novel de novo frameshift ARX variant identified by whole-exome sequencing: a case report.

A 2-year-old girl with frequent seizures, global developmental delay, and autistic features was referred to our hospital. She was the second child of consanguineous non-affected parents. She had a high forehead, mildly prominent ears, and prominent nasal root. A generalized epileptiform discharge was noted in her electroencephalography. Brain MRI revealed corpus callosum agenesis, cerebral atrophy, and a left parafalcine cyst. The WES result showed a likely pathogenic variant identified as a novel de novo deletion in exon 4 of the ARX gene, which creates a frameshift variant. The patient is on dual therapy of antiepilepsy drugs, physiotherapy, speech therapy, occupational therapy, and oral motor exercises. Variants in the ARX gene can result in various phenotypes in males transmitted from asymptomatic carrier females. However, several reports showed that the ARX variants might cause phenotypes in females with milder symptoms than affected males. We report a novel de novo ARX variant in an affected female with a NDD. Our study confirms that the ARX variant might cause remarkable pleiotropy phenotypes in females. Moreover, WES could help to identify the pathogenic variant in NDD patients with diverse phenotypes.

Bmi1 suppresses protein synthesis and promotes proteostasis in hematopoietic stem cells.

The polycomb complex component Bmi1 promotes the maintenance of stem cells in multiple postnatal tissues, partly by negatively regulating the expression of p16Ink4a and p19Arf, tumor suppressors associated with cellular senescence. However, deficiency for p16Ink4a and p19Arf only partially rescues the function of Bmi1-deficient stem cells. We conditionally deleted Bmi1 from adult hematopoietic cells and found that this slowly depleted hematopoietic stem cells (HSCs). Rather than inducing senescence, Bmi1 deficiency increased HSC division. The increased cell division was caused partly by increased Aristaless-related homeobox (ARX) transcription factor expression, which also increased ribosomal RNA expression. However, ARX deficiency did not rescue HSC depletion. Bmi1 deficiency also increased protein synthesis, protein aggregation, and protein ubiquitylation independent of its effects on cell division and p16Ink4a, p19Arf, and ARX expression. Bmi1 thus promotes HSC quiescence by negatively regulating ARX expression and promotes proteostasis by suppressing protein synthesis. This highlights a new connection between the regulation of stem cell maintenance and proteostasis.

Generation of FLAG-tagged Arx knock-in mouse model.

The Aristaless-related homeobox (ARX) is a paired-like homeodomain transcription factor playing important roles in brain development. Patients with mutations in ARX have a spectrum of neurodevelopmental disorders such as epilepsy, intellectual disability, and autism spectrum disorder, with or without structural abnormalities of the brain such as lissencephaly (smooth brain), microcephaly (small brain), and/or agenesis of the corpus callosum. Mouse models have provided important clues on the pathophysiologic roles of ARX in these disorders. However, successfully isolating specific in vivo complexes of ARX, with DNA and proteins, has remained as a challenge. To facilitate in vivo detection of ARX complexes, we generated a mouse line containing one epitope of FLAG-tag (1 × FLAG) targeted at the translational start site of the endogenous Arx gene using CRSPR/Cas9 strategy. Homozygous Flag-Arx mice are viable and fertile without gross abnormality, suggesting that the FLAG-tag does not perturb the normal function of ARX. Using a FLAG antibody, we successfully detected ARX with immunofluorescent staining and pulled down ARX in embryonic brain tissues. This Flag-Arx mouse line will be a useful tool to isolate ARX complexes from mouse tissues for many applications.

Further Delineation of Duplications of ARX Locus Detected in Male Patients with Varying Degrees of Intellectual Disability.

The X-linked gene encoding aristaless-related homeobox (ARX) is a bi-functional transcription factor capable of activating or repressing gene transcription, whose mutations have been found in a wide spectrum of neurodevelopmental disorders (NDDs); these include cortical malformations, paediatric epilepsy, intellectual disability (ID) and autism. In addition to point mutations, duplications of the ARX locus have been detected in male patients with ID. These rearrangements include telencephalon ultraconserved enhancers, whose structural alterations can interfere with the control of ARX expression in the developing brain. Here, we review the structural features of 15 gain copy-number variants (CNVs) of the ARX locus found in patients presenting wide-ranging phenotypic variations including ID, speech delay, hypotonia and psychiatric abnormalities. We also report on a further novel Xp21.3 duplication detected in a male patient with moderate ID and carrying a fully duplicated copy of the ARX locus and the ultraconserved enhancers. As consequences of this rearrangement, the patient-derived lymphoblastoid cell line shows abnormal activity of the ARX-KDM5C-SYN1 regulatory axis. Moreover, the three-dimensional (3D) structure of the Arx locus, both in mouse embryonic stem cells and cortical neurons, provides new insight for the functional consequences of ARX duplications. Finally, by comparing the clinical features of the 16 CNVs affecting the ARX locus, we conclude that—depending on the involvement of tissue-specific enhancers—the ARX duplications are ID-associated risk CNVs with variable expressivity and penetrance.

Deregulation of microtubule organization and RNA metabolism in Arx models for lissencephaly and developmental epileptic encephalopathy.

X-linked lissencephaly with abnormal genitalia (XLAG) and developmental epileptic encephalopathy-1 (DEE1) are caused by mutations in the Aristaless-related homeobox (ARX) gene, which encodes a transcription factor responsible for brain development. It has been unknown whether the phenotypically diverse XLAG and DEE1 phenotypes may converge on shared pathways. To address this question, a label-free quantitative proteomic approach was applied to the neonatal brain of Arx knockout (ArxKO/Y) and knock-in polyalanine (Arx(GCG)7/Y) mice that are respectively models for XLAG and DEE1. Gene ontology and protein–protein interaction analysis revealed that cytoskeleton, protein synthesis and splicing control are deregulated in an allelic-dependent manner. Decreased α-tubulin content was observed both in Arx mice and Arx/alr-1(KO) Caenorhabditis elegans ,and a disorganized neurite network in murine primary neurons was consistent with an allelic-dependent secondary tubulinopathy. As distinct features of Arx(GCG)7/Y mice, we detected eIF4A2 overexpression and translational suppression in cortex and primary neurons. Allelic-dependent differences were also established in alternative splicing (AS) regulated by PUF60 and SAM68. Abnormal AS repertoires in Neurexin-1, a gene encoding multiple pre-synaptic organizers implicated in synaptic remodelling, were detected in Arx/alr-1(KO) animals and in Arx(GCG)7/Y epileptogenic brain areas and depolarized cortical neurons. Consistent with a conserved role of ARX in modulating AS, we propose that the allelic-dependent secondary synaptopathy results from an aberrant Neurexin-1 repertoire. Overall, our data reveal alterations mirroring the overlapping and variant effects caused by null and polyalanine expanded mutations in ARX. The identification of these effects can aid in the design of pathway-guided therapy for ARX endophenotypes and NDDs with overlapping comorbidities.

Generation of an isogenic gene-corrected iPSC line (OGHFUi001-A-1) from a type 1 early infantile epileptic encephalopathy (EIEE1) patient with a hemizygous R330L mutation in the ARX gene

Type 1 early infantile epileptic encephalopathy (EIEE1) is a rare X-link neurodevelopmental disorder caused by mutations in the ARX gene. The mechanism remains unclear due to the lack of cellular models for the disease. We previously have generated an iPSC line (OGHFUi001-A) from a male EIEE1 patient with a hemizygous R330L mutation in the ARX gene. Here we corrected the R330L mutation genetically using CRISPR/Cas9 technology to generate an isogenic control, which was an ideal control to investigate the pathogenesis of the mutation in this disease.

Generation of an induced pluripotent stem cell line from an Ohtahara syndrome patient with the hemizygous mutation p.Q503Afs*28 (c.1507_1508del) in the ARX gene

Aristaless-related homeobox (ARX)-related disorders are recessive X-linked intellectual disability disorders. We encountered a patient with a hemizygous mutation (c.1507_1508del) showing intellectual disability, early-onset epileptic encephalopathy and Ohtahara syndrome. The patient had female genitals, but an XY karyotype. We established an induced pluripotent stem cell (iPSC) line from the peripheral blood mononuclear cells (PBMCs) of a six-month Chinese child with a hemizygous mutation (c.1507_1508del) in ARX. The PBMCs were reprogrammed with Sendai viral vectors. The iPSCs showed stable amplification, pluripotency-related gene expression, and trilineage differentiation potential. Karyotype analysis of the iPSCs showed 23 pairs of chromosomes with normal structure and sex chromosome is XY.

Early infantile epileptic encephalopathy type 1 and 2: literature review and own observation

Epileptic encephalopathies and developmental encephalopathies are a group of severe disorders characterized by a delay or regression of cognitive and behavioral skills that develop as a result of resistant epileptic seizures. Because of the clinical and genetic heterogeneity of these disorders, next-generation sequencing is an important part of the examination of patients to identify the genetic etiology of the disorder and the appointment of targeted antiepileptic therapy. The article presents modern views on 1 and 2 types epileptic encephalopathies caused by pathogenic mutations of the ARX and CDKL5 genes. The main features of clinical symptoms, data of additional instrumental methods of examination and possible variations of targeted use of combinations of antiepileptic drugs in these disorders are presented. A case report of a patient with a CDKL5 gene mutation is described.