BACKGROUND:Studies have found that inhibition of tumor necrosis factor receptor-associated factor 6 improves myocardial function and promotes myocardial autophagy in sepsis,but the specific mechanism is not clear.OBJECTIVE:To explore the effect of inhibiting tumor necrosis factor receptor-associated factor 6-regulated mTORC1/ULK1 autophagy signaling pathway on myocardial injury in sepsis mice.METHODS:Thirty male Kunming mice were randomly divided into sham operation group,cecal ligation and puncture group(model group),model+tumor necrosis factor receptor-associated factor 6 specific inhibitor C25-140(model+C)group,model+C25-140+autophagy inhibitor 3-methyladenine(model+C+3-MA)group,and model+C25-140+mTORC1-specific agonist MHY1485(model+C+M)group.The cecum of mice in the sham operation group was not ligated or punctured.The mice in the other groups underwent cecum ligation and puncture to establish the mouse sepsis model.C25-140,3-methyladenine,and MHY1485 were intraperitoneally injected 0.5 hours after surgery according to the grouping.Myocardial tissue was obtained 24 hours after surgery.Hematoxylin-eosin staining was used to evaluate myocardial inflammatory lesions.Transmission electron microscopy was used to observe the changes in the autophagic bodies and mitochondrial microstructures of myocardial cells.TUNEL assay was used to detect myocardial cell apoptosis.PCR was used to detect the relative expression of tumor necrosis factor receptor-associated factor 6 mRNA.Western blot assay was used to detect the expression of related proteins.RESULTS AND CONCLUSION:(1)Compared with sham operation group,myocardial inflammatory cell infiltration and fibrous edema were observed in the model group.The mitochondria of the cells were obviously swollen,and autophagosomes were occasionally seen;cardiomyocyte apoptosis increased significantly;the expression of tumor necrosis factor receptor-associated factor 6,phosphorylated nuclear factor κB P65/P65,p-mTOR/mTOR,p-ULK1/ULK1,P62 and Bax protein increased,and the expression of Bcl2 protein decreased(P＜0.05).(2)Compared with the model group,myocardial inflammation and fibrous edema were alleviated in the model+C group.Myocardial mitochondrial swelling was reduced and autophagosomes increased;cardiomyocyte apoptosis decreased;the expression of phosphorylated nuclear factor κB P65/nuclear factor-κB P65,p-mTOR/mTOR,p-ULK1/ULK1,P62,and Bax protein decreased,while the Beclin-1 and Bcl2 protein increased(P＜0.05).(3)Compared with the model+C group,myocardial autophagosomes decreased and myocardial mitochondrial swelling was more obvious in the model+C+3-MA group.Myocardial inflammation was aggravated;myocardial cell apoptosis increased;the expression of phosphorylated nuclear factor κB P65/nuclear factor κB P65,P62,and Bax protein increased,and the Beclin-1 and Bcl2 protein decreased(P＜0.05).(4)Compared with the model+C group,the expression of p-mTOR/mTOR and p-ULK1/ULK1 in the model+C+M group increased,and the Beclin-1 and microtubule-associated protein 1 light chain 3 Ⅱ/Ⅰ protein expression decreased(P＜0.05).It is concluded that inhibition of tumor necrosis factor receptor-associated factor 6 regulates mTORC1/ULK1 autophagy signal to promote myocardial autophagy and participate in the protection of myocardial injury in sepsis.

Objective:To summarize the clinical characteristics of children with mitochondrial short-chain enoyl-CoA hydratase-1 deficiency (ECHS1D) caused by c.489G>A (p.Pro163=) compound heterozygous variants in the ECHS1 gene, and to explore genotype-phenotype correlations.Methods:A case series study was performed to analyze clinical, biochemical, metabolic, imaging, genetic, treatment and follow-up outcomes of 24 children with ECHS1 gene c.489G>A(p.Pro163=) variant, who were diagnosed in the Department of Neurology, Beijing Children′s Hospital from July 2010 to June 2024. Disease severity was assessed using the Newcastle Paediatric Mitochondrial Disease Scale, and Fisher exact test was applied to compare the improvement rate between valine-restricted and non-restricted groups.Results:These 24 children were all diagnosed after 2022, with a disease duration of 3.35 (1.25, 6.52) years at diagnosis. A total of 8 children initially had negative genetic results, and were finally confirmed by abnormal splicing of ECHS1 gene via skin fibroblast RNA sequencing, with the longest diagnostic time of 14 years. All 24 children presented with Leigh syndrome, including 11 boys and 13 girls, with an onset age of 1.46 (0.96, 2.79) years; 16 children (67%) were mild cases. Common initial symptoms included developmental delay (9 cases) and paroxysmal dystonia (9 cases), followed by developmental regression (3 cases), nystagmus (2 cases), and epilepsy (1 case). Main manifestations were dystonia (18 cases), developmental regression (14 cases), nystagmus (12 cases), developmental delay (11 cases), ataxia (10 cases), vision loss (9 cases), seizures (2 cases), and hearing impairment (1 case). Among 22 children who underwent blood and urine metabolic screening, 21 children (95%) had elevated urinary 2, 3-dihydroxy-2-methylbutyric acid and 19 children (86%) had elevated urinary S-(2-hydroxypropyl) cysteamine. All 24 children had symmetric abnormal signals in bilateral globus pallidus on cranial magnetic resonance imaging, 10 children had isolated globus pallidus involvement, and other common involved sites included caudate nucleus and brainstem (9 cases each), putamen (7 cases), and cerebral white matter (5 cases). At last follow-up, all 24 children survived, with a follow-up duration of 5.40 (2.75, 8.02) years and a maximum age of 17.8 years; 17 children (71%) had varying degrees of clinical improvement. There was no statistical difference in the improvement rate between children with or without valine-restricted diet (12/14 vs. 5/8, P=0.309). A total of 18 pathogenic variants in the ECHS1 gene were identified among 24 children, 13 of which were distributed in exons 7 and 8; those carrying c.308T>C, c.523G>A, c.796A>G, and c.832G>A variants were mostly severe cases. Conclusions:Children carrying ECHS1 gene c.489G>A(p.Pro163=) compound heterozygous variants face significant diagnostic delay. Clinical awareness of this synonymous variant needs further improvement for timely diagnosis. All these cases present as Leigh syndrome, mostly mild, with no clear genotype-phenotype correlation identified.

Objective:To summarize the long-term efficacy of nicotinamide in treating pediatric early-onset progressive encephalopathy with brain edema and (or) leukoencephalopathy-2 (PEBEL2) caused by NAXD gene variation .Methods:This was a case report conducted from February 2019 to January 2025. The long-term efficacy of nicotinamide was observed by following up a child with PEBEL2 who received the treatment in the Department of Neurology, Beijing Children′s Hospital Affiliated to Capital Medical University. The clinical data included changes in skin lesions, neurological symptoms. The modified Rankin scale (mRS) was used to evaluate the recovery of neurological function.Results:A boy was diagnosed with PEBEL2 caused by NAXD gene variation via genetic testing at Beijing Children′s Hospital Affiliated to Capital Medical University in February 2019, when he was 4 years and 6 months of age. Immediately after diagnosis, nicotinamide treatment was initiated at an initial dose of 100 mg/d, which was increased by 100 mg per week and gradually increased to 500 mg/d; meanwhile, other therapeutic drugs were gradually discontinued. After 1 year and 8 months of treatment, the child′s skin lesions had completely resolved; at the 2-year follow-up, dystonia in both upper limbs and swallowing dysfunction was alleviated significantly; by 2.5-year follow-up, his cognitive function also showed improvement. When the child was treated with 500 mg/d for 3 years, a rash appeared around the mouth. After the dose was reduced to 250 mg/d, the rash resolved, and the dose of 250 mg/d was maintained until the last follow-up. At the last follow-up in January 2025, the child was 10 years and 5 months of age. His mRS score decreased from 5 (before treatment) to 4. During the 6-year of continuous nicotinamide treatment, the child′s condition remained stable without progression. Drug-related skin rashes occurred, but no severe drug-related adverse reactions were observed.Conclusions:PEBEL2 is a treatable mitochondrial disease. Nicotinamide treatment can effectively improve skin lesions and neurological symptoms in PEBEL2 patients, and the long-term administration demonstrates a favorable safety profile.

BACKGROUND:Studies have found that inhibition of tumor necrosis factor receptor-associated factor 6 improves myocardial function and promotes myocardial autophagy in sepsis,but the specific mechanism is not clear.OBJECTIVE:To explore the effect of inhibiting tumor necrosis factor receptor-associated factor 6-regulated mTORC1/ULK1 autophagy signaling pathway on myocardial injury in sepsis mice.METHODS:Thirty male Kunming mice were randomly divided into sham operation group,cecal ligation and puncture group(model group),model+tumor necrosis factor receptor-associated factor 6 specific inhibitor C25-140(model+C)group,model+C25-140+autophagy inhibitor 3-methyladenine(model+C+3-MA)group,and model+C25-140+mTORC1-specific agonist MHY1485(model+C+M)group.The cecum of mice in the sham operation group was not ligated or punctured.The mice in the other groups underwent cecum ligation and puncture to establish the mouse sepsis model.C25-140,3-methyladenine,and MHY1485 were intraperitoneally injected 0.5 hours after surgery according to the grouping.Myocardial tissue was obtained 24 hours after surgery.Hematoxylin-eosin staining was used to evaluate myocardial inflammatory lesions.Transmission electron microscopy was used to observe the changes in the autophagic bodies and mitochondrial microstructures of myocardial cells.TUNEL assay was used to detect myocardial cell apoptosis.PCR was used to detect the relative expression of tumor necrosis factor receptor-associated factor 6 mRNA.Western blot assay was used to detect the expression of related proteins.RESULTS AND CONCLUSION:(1)Compared with sham operation group,myocardial inflammatory cell infiltration and fibrous edema were observed in the model group.The mitochondria of the cells were obviously swollen,and autophagosomes were occasionally seen;cardiomyocyte apoptosis increased significantly;the expression of tumor necrosis factor receptor-associated factor 6,phosphorylated nuclear factor κB P65/P65,p-mTOR/mTOR,p-ULK1/ULK1,P62 and Bax protein increased,and the expression of Bcl2 protein decreased(P＜0.05).(2)Compared with the model group,myocardial inflammation and fibrous edema were alleviated in the model+C group.Myocardial mitochondrial swelling was reduced and autophagosomes increased;cardiomyocyte apoptosis decreased;the expression of phosphorylated nuclear factor κB P65/nuclear factor-κB P65,p-mTOR/mTOR,p-ULK1/ULK1,P62,and Bax protein decreased,while the Beclin-1 and Bcl2 protein increased(P＜0.05).(3)Compared with the model+C group,myocardial autophagosomes decreased and myocardial mitochondrial swelling was more obvious in the model+C+3-MA group.Myocardial inflammation was aggravated;myocardial cell apoptosis increased;the expression of phosphorylated nuclear factor κB P65/nuclear factor κB P65,P62,and Bax protein increased,and the Beclin-1 and Bcl2 protein decreased(P＜0.05).(4)Compared with the model+C group,the expression of p-mTOR/mTOR and p-ULK1/ULK1 in the model+C+M group increased,and the Beclin-1 and microtubule-associated protein 1 light chain 3 Ⅱ/Ⅰ protein expression decreased(P＜0.05).It is concluded that inhibition of tumor necrosis factor receptor-associated factor 6 regulates mTORC1/ULK1 autophagy signal to promote myocardial autophagy and participate in the protection of myocardial injury in sepsis.

Objective:To summarize the clinical characteristics of children with mitochondrial short-chain enoyl-CoA hydratase-1 deficiency (ECHS1D) caused by c.489G>A (p.Pro163=) compound heterozygous variants in the ECHS1 gene, and to explore genotype-phenotype correlations.Methods:A case series study was performed to analyze clinical, biochemical, metabolic, imaging, genetic, treatment and follow-up outcomes of 24 children with ECHS1 gene c.489G>A(p.Pro163=) variant, who were diagnosed in the Department of Neurology, Beijing Children′s Hospital from July 2010 to June 2024. Disease severity was assessed using the Newcastle Paediatric Mitochondrial Disease Scale, and Fisher exact test was applied to compare the improvement rate between valine-restricted and non-restricted groups.Results:These 24 children were all diagnosed after 2022, with a disease duration of 3.35 (1.25, 6.52) years at diagnosis. A total of 8 children initially had negative genetic results, and were finally confirmed by abnormal splicing of ECHS1 gene via skin fibroblast RNA sequencing, with the longest diagnostic time of 14 years. All 24 children presented with Leigh syndrome, including 11 boys and 13 girls, with an onset age of 1.46 (0.96, 2.79) years; 16 children (67%) were mild cases. Common initial symptoms included developmental delay (9 cases) and paroxysmal dystonia (9 cases), followed by developmental regression (3 cases), nystagmus (2 cases), and epilepsy (1 case). Main manifestations were dystonia (18 cases), developmental regression (14 cases), nystagmus (12 cases), developmental delay (11 cases), ataxia (10 cases), vision loss (9 cases), seizures (2 cases), and hearing impairment (1 case). Among 22 children who underwent blood and urine metabolic screening, 21 children (95%) had elevated urinary 2, 3-dihydroxy-2-methylbutyric acid and 19 children (86%) had elevated urinary S-(2-hydroxypropyl) cysteamine. All 24 children had symmetric abnormal signals in bilateral globus pallidus on cranial magnetic resonance imaging, 10 children had isolated globus pallidus involvement, and other common involved sites included caudate nucleus and brainstem (9 cases each), putamen (7 cases), and cerebral white matter (5 cases). At last follow-up, all 24 children survived, with a follow-up duration of 5.40 (2.75, 8.02) years and a maximum age of 17.8 years; 17 children (71%) had varying degrees of clinical improvement. There was no statistical difference in the improvement rate between children with or without valine-restricted diet (12/14 vs. 5/8, P=0.309). A total of 18 pathogenic variants in the ECHS1 gene were identified among 24 children, 13 of which were distributed in exons 7 and 8; those carrying c.308T>C, c.523G>A, c.796A>G, and c.832G>A variants were mostly severe cases. Conclusions:Children carrying ECHS1 gene c.489G>A(p.Pro163=) compound heterozygous variants face significant diagnostic delay. Clinical awareness of this synonymous variant needs further improvement for timely diagnosis. All these cases present as Leigh syndrome, mostly mild, with no clear genotype-phenotype correlation identified.

Objective:To summarize the long-term efficacy of nicotinamide in treating pediatric early-onset progressive encephalopathy with brain edema and (or) leukoencephalopathy-2 (PEBEL2) caused by NAXD gene variation .Methods:This was a case report conducted from February 2019 to January 2025. The long-term efficacy of nicotinamide was observed by following up a child with PEBEL2 who received the treatment in the Department of Neurology, Beijing Children′s Hospital Affiliated to Capital Medical University. The clinical data included changes in skin lesions, neurological symptoms. The modified Rankin scale (mRS) was used to evaluate the recovery of neurological function.Results:A boy was diagnosed with PEBEL2 caused by NAXD gene variation via genetic testing at Beijing Children′s Hospital Affiliated to Capital Medical University in February 2019, when he was 4 years and 6 months of age. Immediately after diagnosis, nicotinamide treatment was initiated at an initial dose of 100 mg/d, which was increased by 100 mg per week and gradually increased to 500 mg/d; meanwhile, other therapeutic drugs were gradually discontinued. After 1 year and 8 months of treatment, the child′s skin lesions had completely resolved; at the 2-year follow-up, dystonia in both upper limbs and swallowing dysfunction was alleviated significantly; by 2.5-year follow-up, his cognitive function also showed improvement. When the child was treated with 500 mg/d for 3 years, a rash appeared around the mouth. After the dose was reduced to 250 mg/d, the rash resolved, and the dose of 250 mg/d was maintained until the last follow-up. At the last follow-up in January 2025, the child was 10 years and 5 months of age. His mRS score decreased from 5 (before treatment) to 4. During the 6-year of continuous nicotinamide treatment, the child′s condition remained stable without progression. Drug-related skin rashes occurred, but no severe drug-related adverse reactions were observed.Conclusions:PEBEL2 is a treatable mitochondrial disease. Nicotinamide treatment can effectively improve skin lesions and neurological symptoms in PEBEL2 patients, and the long-term administration demonstrates a favorable safety profile.

Objective:To explore the effect of post-pyloric feeding by spiral nasoenteric tubes on the prognosis of critically ill patients with acute gastrointestinal injury (AGI) grade Ⅱ.Methods:A retrospective study was performed to analyze the clinical data of critically ill adult patients with AGI grade Ⅱ, who were enrolled in three randomized controlled trials conducted by Guangdong Provincial People's Hospital for post-pyloric tube placement between April 2012 and May 2019. Data including demographic characteristics, serological indicators of nutrition, the tube tip position confirmed by abdominal X-ray 24 h after tube insertion, and intensive care unit (ICU), 28-day and hospital mortality were collected. Patients were divided into the post-pyloric feeding group and gastric feeding group according to the tube tip position. Propensity score matching method was used to perform 1:1 matching, and the differences of each index between the two groups were compared after matching. Then the influencing factors of P<0.1 were included in multivariate logistic regression analysis to investigate the potential ICU mortality risk factors of critically ill patients with AGI gradeⅡ. Factors with 0.1 level of significance from the univariate analysis were considered in the multivariate analysis. Results:There were 90 patients in post-pyloric feeding group and 90 patients in the gastric feeding group. Demographics and clinical characteristics of study population were well balanced between the two groups after matching. ICU, 28-day and hospital mortality in the post-pyloric feeding group were significantly lower than those in the gastric feeding group (4.4% vs 15.6%, 14.4% vs 27.8%, 6.7% vs 17.8%, all P < 0.05). Multivariate logistic regression analysis indicated that post-pyloric feeding was an independent protective factor [odds ratio ( OR)=0.295, 95% confidence internal (95% CI): 0.091-0.959, P=0.042] and APACHEⅡ score was an independent risk factor ( OR=1.111, 95% CI: 1.025-1.203, P=0.010) for ICU mortality of critically ill patients with AGI gradeⅡ. Conclusions:Post-pyloric feeding for critically ill patients with AGI grade Ⅱ could decrease ICU mortality and is an independent protective factor against mortality.

Characterized by impaired neuromuscular transmission, congenital myasthenic syndromes (CMS) are a group of genetic disorders.The main manifestations include fatigue and weakness of skeletal muscle, with most onset in infant or early childhood.The common cause of death is respiratory failure, with high disability rate.With the improvement of gene sequencing technology and the in-depth study on the structure and function of pathogenic proteins, the pathogenesis of the disease has been deeply understood in the past 20 years.Early diagnosis and treatment can significantly improve the symptoms in patients.In this manuscript, the etiology, clinical characteristics, diagnosis and treatment of CMS are reviewed.

Objective:To explore the phenotypes and genotypes of molybdenum cofactor deficiency type B (MoCD-B) manifested as Leigh-like syndrome.Methods:The clinical data, laboratory tests, neuroimaging and gene results of one patient diagnosed as MoCD-B at Beijing Children′s Hospital and Hebei Children′s Hospital in December 2018 were collected. Related literature was searched and reviewed at Wanfang Data Knowledge Service Platform, China National Knowledge Infrastructure and PubMed (up to September 2020) by using terms "MOCS2" "molybdenum cofactor deficiency" "Leigh-like syndrome,MOCS2" "molybdenum cofactor deficiency, Leigh-like syndrome". The phenotypes and genotypes of MoCD-B were summarized.Results:A 7 months and 14 days old boy with the chief complaint of "cough for 6 days, abnormal posture for 4 days and fever for 2 days" was admitted to Hebei Children′ Hospital on December 2018. His abnormal posture presented as opisthotonos accompanied with dysphagia, without seizures. His previous psychomotor development was described as normal. He was born at term after an uneventful pregnancy to non-consanguineous parents. Blood test showed a slightly increased lactic acid and a significantly decreased uric acid. Urine metabolism test showed an obviously increased xanthine and hypoxanthine. Brain magnetic resonance imaging showed hyperintense signal on T2 weighted image and fluid attenuated inversion recovery in bilateral globus pallidus and pedunculus cerebri. The patient was diagnosed with Leigh-like syndrome. No obvious improvement was achieved after cocktail therapy and symptomatic treatment. The whole exome sequencing showed that the patient carried a homozygous variant of MOCS2 gene, c.19G>T(p.Val7Phe), which was a previously reported pathogenic site in the literature and could cause MoCD-B. His parents carried a heterozygous variant respectively. A total of 41 MoCD-B cases with MOCS2 gene variants were collected through literature review and our study, among which 30 cases had full medical records. The onset ages of 23 (77%) cases were in neonate, manifesting with severe encephalopathy, including neonatal-onset intractable seizures, developmental delay, laboratory abnormalities included very low levels of serum and urinary uric acid, increased urinary levels of xanthine and hypoxanthine. Cranial imaging showed cerebral atrophy, cystic encephalomalacia, etc. The onset ages of 7 patients varied from 5 months to 23 years. Four cases had normal psychomotor development before disease onset. Neurological disorders appeared acutely or exacerbated after external triggers and all of them had basal ganglia involvement. Among the 30 cases, 3 cases had a relatively milder phenotype with the ability of brief communication and walking without or with support.Conclusions:Molybdenum cofactor deficiency is a rare disease. Most cases had severe phenotypes and poor outcomes, but some cases may have mild phenotype. MoCD-B caused by MOCS2 gene variants may manifest as Leigh-like syndrome with a normal psychomotor development before the trigger of infection strike. Hypouricemia, xanthinuria and hypoxanthinuria can be indicators of the disease. The presence of MOCS2 gene variants would confirm a final diagnosis.

Objective: To summarize the clinical and genetic characteristics of children with mitochondrial epilepsy. Methods: Clinical data of 62 children who were clinically and genetically diagnosed with mitochondrial epilepsy by the Department of Neurology, Beijing Children′s Hospital from October 2011 to December 2018 were analyzed retrospectively, and the control of epilepsy was followed up. T test or χ² test were used to analyze the related factors affecting the prognosis of epilepsy between the effective group and the ineffective group. Results: Of the 62 patients, 33 were male and 29 were female. The age of onset was 3.38 (0-12.00) years; for the type of seizures, 68% (42/62) of the patients had focal seizures, generalized or secondary generalized tonic-clonic seizures were seen in 32% (20/62), myoclonic seizures in 23% (14/62), spastic seizures in 7 cases, tonic seizures in 4 cases, absence seizure, atonic seizure and clonic seizure in 1 case each; 16 cases (26%) had status epilepticus, of whom 6 cases had epilepsia partialis continua; 52% (32/62) had 2 or more types of seizures. The clinical phenotypes were mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) in 29 cases, Leigh syndrome (LS) in 11 cases, combined oxidative phosphorylation deficiency in 6 cases, myoclonus epilepsy with ragged-red fibers in 5 cases, Alpers syndrome in 4 cases, pontocerebellar hypoplasia type 6 and mitochondrial DNA depletion syndrome 9 in 2 cases each, mitochondrial complex Ⅰ deficiency nuclear type 20, progressive cavitating leukoencephalopathy, and biotinidase deficiency in 1 case each. Of the 62 cases, 40 cases (65%) had mitochondrial DNA (mtDNA) variations, of which 26 cases had m.3243A>G variants, 6 cases had m.8344A>G variants, and 3 cases had m.8993T>G/C variants, m.3271T>C, m.3481G>A, m.3946G>A, m.13094T>C, m.14487T>C variant was in 1 case each; nuclear DNA (nDNA) variations were identified in 22 cases (35%), of which 7 cases carrying variations in mitochondrial ammonia acyl tRNA synthetase coding gene, mutations in POLG and the gene encoding complex Ⅰ were in 4 cases each, variations in SUCLG1 and SDHA genes were in 2 cases each, and variations in PDHA1, BTD and TRIT1 genes were in 1 case each. Forty-three patients were followed up, and the follow-up time was 20 (3-84) months. According to the follow-up results, the anti-epilepsy treatment was effective in 19 cases (44%) and ineffective in other 24 cases (56%). The onset age of the effective group was 3.42 (0-11.50) years and that of the ineffective group was 0.92 (0-9.50) years. The onset duration of the effective group was 0 (0-7.00) years and that of the ineffective group was 0 (0-4.83) years. There was no significant difference between the effective group and the ineffective group (t=1.662, 0.860; P=0.104, 0.395). In the effective group and the ineffective group, 12 cases and 9 cases used less than 2 kinds of antiepileptic drugs, 7 cases and 15 cases used more than or equal to 2 kinds of antiepileptic drugs, 13 and 15 cases had first epilepsy, 6 and 9 cases had non-first epilepsy, 14 and 11 cases had mtDNA variation, 5 and 13 cases had nDNA variation, respectively. There was no significant difference between the two groups (χ²=2.794, 0.164, 3.380; P=0.095, 0.686, 0.066). Conclusions The types of seizures with mitochondrial epilepsy in children varied, with focal motor seizures being the most common, followed by generalized or secondary generalized tonic-clonic seizures. Most children have more than two types of seizures. MELAS is the most common clinical phenotype, followed by LS; mtDNA variation is the dominant gene variation, of which m.3243A>G variation is the most common hotspot variation, followed by gene variation encoding mitochondrial aminoacyl tRNA synthase.