Study On Epilepsy Associated With Gatorl Complex And Literature Review

Research backgroundGatorl complex is located in the upstream of the signal transduction pathway of the mechanical target of rapamycin(MTOR),and as a target repressor,it can negatively regulate the mTORC1 pathway,thus affecting the development and function of the brain.Gatorl complex consists of DEPDC5 protein(DEP Domain-Containing Protein 5,DEPDC5),Nitrogenase Regulator-Like 2 and 3 proteins(NPRL2,NPRL3).The gene variation of the above components can cause dysfunction of Gatorl protein complex,and then increase the activity of mTORC1 abnormally,resulting in clinical manifestations such as epilepsy and cortical dysplasia.In 2013,Dibbens et al.first discovered that the mutation of DEPDC5 gene was related to FFEVF after sequencing the whole exon group in the family of patients with familial focal epilepsy with variable foci(FFEVF).Then,a variety of epilepsy related to Gatorl complex gene variants were discovered one after another.Including familial focal epilepsy syndrome,sporadic focal epilepsy,other types of epilepsy and epilepsy with abnormal brain structure.Epilepsy associated with Gatorl complex gene variant is often complicated with mental and neurological disorders such as mental disability or autism spectrum disorder.Patients are more likely to develop into drug-resistant epilepsy.In addition,patients with epilepsy associated with Gator complex gene have a high risk of sudden death.Therefore,it is necessary to carry out gene detection and evaluation of the development of mental nervous system in time for clinically suspected cases of this disease,thereby achieving the purpose of early diagnosis and treatment and improving the prognosis.In this study,the main demographic characteristics,attack forms,the clinical phenotype,genotype and prognosis of the disease in the Chinese population were collected,in order to further summarize the clinical and genetic characteristics of the disease and the correlation between genotype and phenotype for genetic counseling,so as to reduce the incidence of the disease and the burden on families and society.Objective1.Collect the clinical data of 5 subjects.2.Sample collection:After obtaining the informed consent of the children and their family members,collect 3.5ml of peripheral venous blood samples of the subjects and their family members.3.Extraction of genomic DNA:DNA was extracted from peripheral venous blood sample with special kit.4.Establishing a gene library:using a specific kit to establish a DNA sample library of the research object.5.Sequencing on the computer:compare the sample concentration and sequencing concentration in the DNA library of the research object,and use illumina sequencer to sequence on the computer.6.Sanger sequencing verification:the mutation sites of the research object that need to be verified are verified by Sanger sequencing,and the corresponding sites of their family members are verified at the same time.7.Using "Gatorl complex","DEPDC5","NPRL2","NPRL3" and"epilepsy" as key words,we searched in CNKI,Wanfang Medical Network,VIP database and Pubmed database,and collected 59 cases of epilepsy related to Gatorl complex in China from 2015 to 2021,and 64 cases of 5 patients in our hospital.Methods1.Collect the clinical data of 5 subjects.2.Sample collection:After obtaining the informed consent of the children and their family members,collect 3.5ml of peripheral venous blood samples of the subjects and their family members.3.Extraction of genomic DNA:DNA was extracted from peripheral venous blood sample with special kit.4.Establishing a gene library:using a specific kit to establish a DNA sample library of the research object.5.Sequencing on the computer:compare the sample concentration and sequencing concentration in the DNA library of the research object,and use Illumina sequencer to sequence on the computer.6.Sanger sequencing verification:the mutation sites of the research object that need to be verified are verified by Sanger sequencing,and the corresponding sites of their family members are verified at the same time.7.With the keywords of "Gatorl complex","DEPDC5","NPRL2","NPRL3" and "epilepsy",we searched in CNKI,Wanfang Medical Network,VIP database and Pubmed database,and collected 59 cases of epilepsy related to Gatorl complex in China from 2015 to 2021,plus 64 cases of 5 patients collected in our hospital.Results1.The proband of family A is the heterozygous mutation of DEPDC5 gene:c.3743G>A is a nonsense mutation that causes the early appearance of stop codon,and it is a maternal mutation.2.There is a heterozygous mutation in DEPDC5 gene of B family proband:c.2570del is a frameshift mutation,which causes the change from glycine to alanine in No.857,advances the downstream stop codon,and leads to the truncated mutation of protein,which is a spontaneous mutation.3.There is a heterozygous mutation in the DEPDC5 gene of C family proband:c.2273A>G is a missense mutation,and this sequence change leads to the change of codon 758 from tyrosine to cysteine(p.Yyr758Cys),which is a paternal mutation.4.There is a heterozygous mutation in NPRL3 gene of proband of D family:c.1585C>T is a missense mutation,and this sequence change leads to the change of codon 529th from arginine to chromocystine(p.Arg529Trp),which is a maternal mutation5.Family E proband showed heterozygous mutation in NPRL3 gene:c.318+1G>A was a splice mutation and it was a maternal mutation.6.A total of 64 cases were included in this study,with the gender ratio of 1:1.The age of onset ranged from 4 days to 25 years,with an average median age of 6.2 years.Focal epileptic seizure was the main form of seizure,accounting for 79%;The mutant gene was mainly DEPDC5 gene,accounting for 76%.A total of 42 mutations were identified in Chinese cases,of which,the loss of mutation accounted for 59%,and the nonsense mutation accounted for 21%.Missense mutations accounted for 38%.Mental retardation accounted for 23%,magnetic resonance imaging abnormalities for 13%,and refractory epilepsy for 37.5%.Conclusion1.In this study,we identified three patients with a mutation in the DEPDC5 gene and two patients with a mutation in the NRPL3 gene.All five cases were new mutations,confirming the pathogenicity of the five gene mutation sites and enriching the gene mutation database of Gatorl complex in China and abroad.2.The clinical manifestations of patients with Gator1 complex-related epilepsy vary greatly,and the members with the same mutation site in the family have different clinical phenotypes,which shows that the clinical manifestations of Gatorl complex related epilepsy are heterogeneous and incomplete.3.Among patients with Gatorl-related epilepsy in China,LOF mutation is more likely to develop into drug-resistant epilepsy than missense mutation,and the incidence of mental retardation is higher than missense mutation in general.