Early-onset epileptic encephalopathies (EEEs): are catastrophic epileptic activity (including clinically frequent seizures and persistent epileptic discharges of EEG between seizures) occurring in the neonatal period or infancy, resulting in cognitive and motor global developmental delays, mental retardation, autism, and other neurological sequelae. Unlike the mature brain, these patients often have microcephaly, cerebral atrophy, and a poor prognosis because the persistent epileptiform activity affects the structure, synaptic plasticity, and neural loop formation of the early developing brain, which can lead to structural and functional brain arrest. eees has a complex etiology. The EEEs have a complex etiology. With the rapid development of modern medicine and increasingly advanced detection methods, some patients with acquired brain injury, structural brain abnormalities, and inherited metabolic diseases can be correctly diagnosed with blood biochemical tests, cranial imaging, and metabolic disease screening, but nearly half of the EEEs have unknown etiology, leading many patients to move around and seek treatment without timely and correct diagnosis and treatment, and is also a problem for This is a problematic issue for pediatric neurologists. Although there are no clear data, recent literature suggests that EEEs of unknown cause are closely associated with genetic mutations and copy number variations. However, the absence of a clear corresponding genotype-phenotype relationship in such children and the fact that the same genetic mutation can have multiple clinical phenotypes increases the difficulty of diagnosis and hinders the development of a genetic information and genetic diagnosis process. Therefore, this article provides a review of the currently known genes that can cause EEEs and their clinical phenotypes, thereby improving the understanding of EEEs among neurologists. Accurate genetic diagnosis can assist physicians in providing patients with disease prognosis, prenatal diagnostic counseling, and developing and providing more individualized treatment plans based on gene function. I. Genetic analysis of EEEs that can be included in specific epilepsy syndromes based on clinical phenotype but of unknown etiology: Early epileptic encephalopathies identified by the International League Against Epilepsy (ILAE) include Otahara syndrome, infantile spasms, severe myoclonic epilepsy in infants, early myoclonic encephalopathy, non-progressive myoclonic encephalopathy and severe focal wandering epilepsy in infants. The relationship between genome-wide copy number variants (CNVs) and EEEs The germ cell is the vehicle for the transmission of genetic information from parent to offspring, and the stability and integrity of its genome is essential for the faithful transmission of genetic information, which is crucial for human health and offspring development. During human germ cell genesis (including mitosis of germ cells and meiosis of germ cells), the genome is subject to various mutations such as point mutations, microsatellite fragment mutations, and structural variation (SV), which affect the stability of the genome. Among them, the newly discovered SV mutations at the submicroscopic level have high rates and large degrees of variation, covering up to 5-10% of the human genome; copy number variants (CNV) are the most common SV isoforms. These SVs mainly originate from various pathways such as DNA damage repair, misreplication, homologous recombination, and chromosomal missegregation during germ cell genesis, and are important causative factors for major diseases such as neurodevelopmental abnormalities, epileptic encephalopathy, and autoimmune encephalopathy. In recent years, international top journals such as Nature and Science have been publishing research findings related to SV, suggesting that SV is becoming a hot spot for research. With the advent of high-throughput genetic testing technologies, some relatively low-frequency potentially pathogenic epilepsy-associated CNVs have been detected in a variety of patients with generalized and focal epilepsy, including CNVs in the 15q13.3, 15q11.2, 16p13.11, and 22q11.2 regions; CNVs were found in 5-10% of epileptic encephalopathies previously thought to be of unknown cause and associated genes.