ABSTRACT
Objective@#To investigate the clinical significance of different samples (the peripheral blood, urine and skeletal muscle) that could be detected the large-scale single deletions directly by using next-generation sequencing in the diagnosis of Kearns-Sayre syndrome (KSS) by concluding the clinical and genetic features of KSS, in order to explore a non-invasive method for diagnosis.@*Methods@#The clinical data, skeletal muscle′s pathology and enzymology and genetic results of individuals with KSS, who were hospitalized from October 2016 to October 2017 in Department of Neurology, Beijing Children′s Hospital, Capital Medical University, were collected.The gene tests were performed by using next generation sequencing technology and long-PCR technology of mitochondrial DNA(mtDNA) and the whole exon in the peripheral blood, urine and skeletal muscle.@*Results@#Four patients were all consistent with the diagnosis criteria of KSS, among whom the age of onset was 8.2 years old on average, and the initial symptoms were statue, ptosis, headache and vomiting, and visual impairment.The common symptoms of the 4 cases were ophthalmoplegia, exercise intolerance, development delay, loss of appetite, hypotonia, muscle weakness, with cerebrospinal fluid protein concentration over 1 000 mg/L, the cerebral magnetic resonance imaging showed that abnormal signals in the brainstem, in addition, white matter, thalamus, basal ganglia, cerebrum and cerebellum atrophy could be found.Moreover, 3 cases had cardiac conduction block.Two cases had maternal family history.Molecular analysis of the 4 cases revealed the large-scale single deletions of mtDNA from the peripheral blood, the urine, the skeletal muscle through the next-generation sequencing, which were m. 6460-15590(9 131 bp del), m.8482-13446(4 964 bp del), m.6831-14981(8 151 bp del), m.7983-15495(7 513 bp del), respectively.Among 3 cases who did pedigree analysis, only the mother of case 4 was detected with the same variation of the proband.@*Conclusions@#KSS is a rare mitochondrial disease, which could be detected with the single large scale mtDNA deletions in the peripheral blood, urine and skeletal muscle.With the development of the methodology, the diagnosis of KSS maybe no longer than depends on the muscle biopsy with the next-generation sequencing.And the possibility to get the positive results in the peripheral blood and urine by the non-invasive method could improve the molecular diagnosis of KSS.
ABSTRACT
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.
ABSTRACT
Objective To investigate the clinical significance of different samples (the peripheral blood,urine and skeletal muscle) that could be detected the large-scale single deletions directly by using next-generation sequencing in the diagnosis of Kearns-Sayre syndrome (KSS) by concluding the clinical and genetic features of KSS,in order to explore a non-invasive method for diagnosis.Methods The clinical data,skeletal muscle's pathology and enzymology and genetic results of individuals with KSS,who were hospitalized from October 2016 to October 2017 in Department of Neurology,Beijing Children's Hospital,Capital Medical University,were collected.The gene tests were performed by using next generation sequencing technology and long-PCR technology of mitochondrial DNA(mtDNA) and the whole exon in the peripheral blood,urine and skeletal muscle.Results Four patients were all consistent with the diagnosis criteria of KSS,among whom the age of onset was 8.2 years old on average,and the initial symptoms were statue,ptosis,headache and vomiting,and visual impairment.The common symptoms of the 4 cases were ophthalmoplegia,exercise intolerance,development delay,loss of appetite,hypotonia,muscle weakness,with cerebrospinal fluid protein concentration over 1 000 mg/L,the cerebral magnetic resonance imaging showed that abnormal signals in the brainstem,in addition,white matter,thalamus,basal ganglia,cerebrum and cerebellum atrophy could be found.Moreover,3 cases had cardiac conduction block.Two cases had maternal family history.Molecular analysis of the 4 cases revealed the large-scale single deletions of mtDNA from the peripheral blood,the urine,the skeletal muscle through the nextgeneration sequencing,which were m.6460-15590(9 131 bp del),m.8482-13446(4 964 bp del),m.6831-14981 (8 151 bp del),m.7983-15495 (7 513 bp del),respectively.Among 3 cases who did pedigree analysis,only the mother of case 4 was detected with the same variation of the proband.Conclusions KSS is a rare mitochondrial disease,which could be detected with the single large scale mtDNA deletions in the peripheral blood,urine and skeletal muscle.With the development of the methodology,the diagnosis of KSS maybe no longer than depends on the muscle biopsy with the next-generation sequencing.And the possibility to get the positive results in the peripheral blood and urine by the non-invasive method could improve the molecular diagnosis of KSS.
ABSTRACT
Objective@#To understand the awareness of sexual knowledge among primary and secondary school students, as well as their attitudes towards school sex education and to provide a reference for school-based sex education.@*Methods@#A total of 5 531 primary and secondary school students were selected from Beijing, Chongqing, Heilongjiang (Harbin and Jiamusi) and Hubei (Wuhan and Xiaogan) by stratified cluster sampling and were investigated with self-reported questionnaire.@*Results@#Sex-related knowledge scored 62.33±19.35, with a pass rate of 61.9%, and the excellent rate 17.5%. Sexual knowledge of junior high school students scored 64.30±19.07, with the pass rate of 64.7%, and the excellent rate 22.0%. A large proportion of primary students reported unaware of pubertal growth and HIV/AIDS-related knowledge, and a large proportion of junior high students unaware of reproductive physiology. Multivariate Logistic regression analysis showed region, grade, gender, and suburban areas were related to the level of sexual knowledge(P<0.05). More than 76.0% primary students and 85.9% middle school students agreed on the importance of school sexuality education. 59.7% of primary school students and 73.3% of junior high school students hoped to include school sexuality education in compulsory education courses; 59.8% of primary school students and 68.3% of junior high school students felt that school sexuality education should be equipped with specialized teachers.@*Conclusion@#Chinese primary and secondary school students are lack of sexual knowledge. As students have strong wills to get more information on sexual knowledge, schools should provide them with more comprehensive and effective sex education through appropriate courses and activities.