Xin-hua Bao

Peking University, Peping, Beijing, China

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Publications (49)

  • Yan-Yan Liu · Xin-Hua Bao · Shuang Wang · [...] · Xi-Ru Wu
    [Show abstract] [Hide abstract] ABSTRACT: To analyze the clinical and SLC2A1 gene mutation characteristics of glucose transporter type 1 deficiency syndrome. The detailed clinical manifestations of six cases were recorded. The laboratory tests including EEG, MRI, blood chemistry, and lumbar puncture were performed. SLC2A1 gene mutations were analyzed by PCR, DNA sequencing and multiplex ligation-dependent probe amplification (MLPA). Patient 1, 2 and 3 had classical clinical symptoms including infantile onset seizures, development delay. Patient 4, 5 and 6 had non-classical clinical symptoms including paroxysmal behavior disturbance, weakness, ataxia, lethargy, especially after fasting or exercise, without severe seizures. The plasma glucose levels were normal. The CSF glucose levels decreased in all the six cases, ranged from 1.10 mmol/L to 2.45 mmol/L, the mean level was 1.68 mmol/L. The CSF glucose/plasma glucose ratios decreased, ranged from 0.16 to 0.51, the mean ratio was 0.34. Four patients had normal EEG. Two patients had focal and diffuse epileptiform discharge, and one of them also had paroxysmal occipital or generalized high-amplitude slow waves during awake and sleep time. MRI abnormalities were found in three patients, patient 1 with mild brain atrophy, patient 3 with bilateral ventricle plump, and patient 4 with high signals in T2 in the frontal and occipital white matter, interpreted as hypomyelination. SLC2A1 gene mutations were found in six cases. Patient 1 has large scale deletion in exon 2. In patient 2 to 6, the mutations were c.741 G>A (E247K), 599delA, 761delA, c.1148 C>A (P383H), c.1198 C>T (R400C) respectively. Two patients were treated with ketogenic diet. The seizures disappeared and development became normal. Three patients responded to frequent meals with snacks. One patient refused any treatments, the symptoms continued to exist. The clinical manifestations of glucose transporter type 1 deficiency syndrome are varied. The common symptoms included infantile onset seizures and various paroxysmal events. These neurologic symptoms generally fluctuated and were influenced by factors such as fasting or fatigue. This feature could be a very important clue for the diagnosis of GLUT1-DS. Lumbar puncture is recommended in patients with episodic CNS symptoms especially after fasting. GLUT1-DS is a treatable neurometabolic disorder, early diagnosis and treatment may improve the prognosis of the patients.
    Article · Jun 2013 · Zhonghua er ke za zhi. Chinese journal of pediatrics
  • Xiao-Li Liu · Xin-Hua Bao · Yi-Nan Ma · [...] · Xi-Ru Wu
    [Show abstract] [Hide abstract] ABSTRACT: To delineate the characteristics of the clinical manifestation, pathology of skeletal muscle and gene mutations of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episode (MELAS) in children. The clinical manifestation, laboratorial data, brain images, muscle pathology and mitochondrial gene mutations were analyzed in 24 patients with MELAS who were diagnosed in Department of Pediatrics, Peking University First Hospital. Their prognosis was evaluated by following up. Symptoms of central nervous system such as stroke-like episodes, vomiting, convulsion and headache were present in all the 24 cases. Nine cases had the symptoms of myopathy. Twenty cases had developmental delay. Short stature, being thin and hairy was very common in these cases. Serum lactate level increased in all the cases, pyruvate increased in 17 cases. Elevated CSF lactate was found in 2 cases. Magnetic resonance imaging (MRI) was performed on 24 cases, out of them 23 were abnormal. The lesions mainly involved cerebral lobes. Occipital lobe was the most common site of lesions. Computed tomography (CT) was performed on 13 cases, low density lesions were present in 10 cases, basal ganglia calcifications in 5 cases. Muscle biopsy was performed on 8 cases, ragged-red fibers (RRF) were found in 4/8 cases, and abnormal accumulation of mitochondria were found in 3/8 cases. The mtDNA gene mutational analysis showed A3243G mutation in these patients. The mutation rates varied from 11.6% to 75.0%. The same mutation were found in 4/5 mothers who had the genetic tests, and the mutation rates of the mothers varied from 15.0% to 23.6%. The clinical information of 11 cases was available through recent following up. Three cases died, the others had some degrees of mental retardation. Children with MELAS had various clinical manifestations. Central nervous system and skeletal muscle were usually involved. Short stature and hypertrichosis were common signs. The prognosis of this disease was disappointing. mtDNA A3243G was the most common mutation in MELAS. Fully understanding the characteristics of its clinical manifestation, laboratory tests, brain image, muscle pathology and molecular features can be helpful to the early diagnosis and treatment.
    Article · Feb 2013 · Zhonghua er ke za zhi. Chinese journal of pediatrics
  • [Show abstract] [Hide abstract] ABSTRACT: Children with refractory epilepsy who suffered from severe liver function impairment during valproic acid (VPA) treatment at routine dosage were studied. The clinical manifestations and therapeutic approaches were investigated in order to improve its diagnosis and management. Clinical information as well as features and management of 4 inpatients who were suffered from intractable epilepsy with severe liver function impairment induced by VPA since 2006 were collected and analyzed, including age of onset of epilepsy, VPA using age and the time when liver injury occurred, clinical manifestations, auxiliary examinations and management. Among the 4 cases, three were male and one was female. The admitted age ranged from 1 - 9 years and 1 month. The course of disease was 25 d - 6 months. They manifested as refractory epilepsy of epilepsia partialis continua which was difficult to control. After using VPA for 62 d (50 - 76 d), all developed severe impairment of liver synthetic function which was not related to the concentration of VPA. One was diagnosed with Alpers syndrome, two were suspicious of Alpers syndrome, and the other was diagnosed gliocytoma after brain biopsy. VPA was stopped immediately and symptomatic therapies were used. Other than that, intravenous injection of L-carnitine in 3 cases recovered the liver function. VPA-associated severe hepatotoxicity can manifest first as impaired liver synthetic function. Besides alanin transaminase and aspartate transaminase, the liver synthetic function test is more important than monitoring of liver enzymatic functions in monitoring for the hepatotoxicity. Intravenous injection of L-carnitine in early stage showed good treatment effect.
    Article · Dec 2012 · Zhonghua er ke za zhi. Chinese journal of pediatrics
  • [Show abstract] [Hide abstract] ABSTRACT: Niemann-Pick disease type C (NP-C), caused by mutations of either NPC1 or NPC2 gene, is an inherited lysosomal lipid storage disorder that is difficult to be diagnosed and treated. NP-C is rarely reported in China and so far very few literatures are available for Chinese clinical workers. To better characterize this disease in China and improve genetic counseling, mutational analyses of NPC1 gene were carried out in 6 unrelated Chinese patients. Clinical data of the probands from 2007 to 2010 were collected and analyzed. All exons of NPC1 were analyzed by direct sequencing. The six cases, four males and two females, included three cases of late infantile subtype and three cases of juvenile subtype. Case one and case six had siblings who suffered from the same disease. The onset of clinical symptoms varied from three to ten years old, and they included progressive cognitive and language impairment, and motion retrogradation. All were caught by focal or generalized seizures from one to four years after the onset. Vertical supranuclear gaze palsy, dysarthria, dysphagia, internal rotation and adduction of bilateral hands and splenomegaly occurred gradually during the disease progression. Five patients had laughter-cataplexy. MRI indicated mild brain atrophy. Sea blue cells and Niemann-Pick cells were presented in bone marrow smears. Activity of acid sphingomyelinase was normal or only slightly lower than controls. Supporting and symptomatic treatments could improve some of the clinical signs. We identified 10 different NPC1 mutations were identified in 12/12 alleles, 3 of which are described for the first time. All mutations were missense mutations, which located throughout the gene with five clustering in the cysteine-rich luminal domain. Homozygous mutation of S865L correlated with a relatively severe juvenile neurological form. NP-C is a rare autosomal recessive lysosomal storage disease that affects intellectual development of children, causing dementia, vegetative state and eventual death. The awareness of NP-C should be raised in the Chinese population. The typical clinical features of this disease include vertical supranuclear gaze palsy, seizures and cataplexy. Laboratory features include the presence of sea blue cells and Niemann-Pick cells in bone marrow smears. NPC1 mutation can be identified in most of these patients and most of them are missense mutations.
    Article · Feb 2012 · Gene
  • [Show abstract] [Hide abstract] ABSTRACT: To summarize the electroclinical characteristics of myoclonic atonic epilepsy (MAE) in children. The clinical data, video electroencephalogram (EEG) and simultaneous electromyography (EMG) of MAE patients were analyzed. The treatment and its effects were followed up. In 47 MAE patients, 25 had a history of febrile seizures (FS), 20 had a family history of FS or epilepsy. All patients had a normal development before the illness. The age of afebrile seizure onset was between 1.4 years to 5.8 years. The first seizure was generalized tonic-clonic seizure (GTCS) in 41 patients (87.2%). All patients had multiple seizure types, including 47 GTCS (97.9%), 34 myoclonic atonic seizures (72.3%), 47 myoclonic seizures (100%), 32 atonic seizures (68.1%), 36 atypical absences (76.6%) and 3 tonic seizures (6.4%). EEG backgrounds were slow or parietal θ rhythm, interictal EEG showed 1-4 Hz (predominant 2-3 Hz) generalized spike and wave or poly spike and wave discharges in all cases. Seizures were controlled by antiepileptic drugs (AEDs) in 41 patients (87.2%). Valproate was used in 37. Lamotrigine was used in 26. Mild mental retardation was observed in 10 children after the onset of the illness. The clinical features of MAE included the following: the development was normal before the onset of the illness; the onset of seizure type was often GTCS. All patients had multiple generalized seizure types. Myoclonic atonic seizure was its characteristic seizure type. EEG showed generalized discharges. Early diagnosis and rational choice of AEDs are important for getting a better prognosis.
    Article · Aug 2011 · Zhonghua er ke za zhi. Chinese journal of pediatrics
  • [Show abstract] [Hide abstract] ABSTRACT: To investigate and analyze the clinical manifestations, classification, therapeutic approaches and follow-up of myasthenia gravis (MG) in children in order to improve its management and prognosis. Clinical information of 135 children with MG, who were diagnosed between January 1993 to January 2008, were collected and retrospectively analyzed. And prospective following-up of these patients were conducted. Among the 135 cases, 59 were males and 76 females, giving the ratio of M/F around 1:1.3. Totally, 115 cases (85.2%) were type I MG (ocular type), of which only 4.2% developed to generalized type during the subsequent clinical course. Type II MG (generalized type)was found in 18 cases (13.4%) and type III MG in two cases(1.5%). The onset age ranged from 5 month to 15 years, with 50.3% before three years and 80.7% before seven years. Upper respiratory tract infection was presented in 26.7% (36/135) of the sick children before the onset of MG. Among the 106 children being followed up, recurrence of the disease identified in 50.9% and the number of relapse ranged from 1 to 9. Altogether, 40.19% (43/106) of the cases were positive for anti-acetylcholine receptor antibodies (AchR-Ab) on the initial examination, and the AchR-Ab postitive rate showed no difference among different clinical subtypes and states. However, during the follow-up, 53% (9/17) of the recurrent cases, who were negative at the first onset, turned to be positive, and 37.97% (30/79) were positive for repetitive nerve stimulation in electromyogram test. There were 71 % (45/63) of all the cases showed reduced levels of CD4+ and/or CD3+ and/or CD8+. Thymus proliferation was found in 5.93% (8/135) through CT scan and thymoma in 1.48% (2/135). Steroids and anti-cholinesterase administration were effective in most cases with good prognosis. Childhood MG, mainly type I, is relatively common in China, with specific characteristics which are different from western patients or adult MG in morbidity, sex distribution, progress, laboratory examination and treatment. The prevalence of myasthenia gravis crisis and mortality rate in MG children is low, and few are accompanied with thymoma. Most MG cases have a satisfied prognosis and few have neuropsychic sequela.
    Article · Jun 2011 · Beijing da xue xue bao. Yi xue ban = Journal of Peking University. Health sciences
  • Guang-na Cao · Xin-hua Bao · Hui Xiong · [...] · Xi-ru Wu
    [Show abstract] [Hide abstract] ABSTRACT: To investigate the association of the polymorphisms of methionine metabolism genes and the phenotype of X-linked adrenoleukodystrophy (X-ALD) and clinical severity. The clinical information of 120 X-ALD patients were analyzed and three genetic variants involved in the methionine metabolism, including cystathionine beta-synthase (CBS) c.844_855ins68, 5-methyltetrahydrofolate-homocysteine-S-methyltransferase (MTR) c.2756A to G, and transcobalamin 2 (TC2) c.776 C to G were analyzed by polymerase chain reaction and sequencing. The association between these polymorphisms and phenotype of X-ALD was studied. The frequency of GG genotype of the TC2 c.776 C/G was higher in patients with central nervous system(CNS) demyelination than in controls (P= 0.012). However, the other two polymorphisms did not show any significant associations with the phenotypes. The GG genotype of TC2 c.776 C/G may contribute to X-ALD phenotype.
    Article · Jun 2011 · Zhonghua yi xue yi chuan xue za zhi = Zhonghua yixue yichuanxue zazhi = Chinese journal of medical genetics
  • Hui Xiong · Xin-Hua Bao · Yue-Hua Zhang · [...] · Xi-Ru Wu
    [Show abstract] [Hide abstract] ABSTRACT: Niemann-Pick disease type C (NP-C), derived from mutation of the NPC1 or NPC2 gene, is one of the recessive lysosomal lipid storage disorders that are difficult to diagnose and treat. Since NP-C has been rarely reported in China, we reviewed 7 patients with NP-C. The 7 patients had been diagnosed with NP-C from 2007 to 2010 at our department and their laboratory and clinical data were analyzed. The 7 patients, 5 males and 2 females, included 4 patients of late infantile subtype and 3 patients of juvenile subtype, in which patients 2 and 3 were siblings. Their clinical symptoms occurred from 4 to 10 years of age, exhibiting as progressive cognitive and language impairment as well as motor retrogression. Six patients were caught by focal or generalized seizures from 1 to 4 years after the onset of the disease. Vertical supranuclear gaze palsy, dysarthria, dysphagia, internal rotation and adduction of bilateral hands and splenomegaly occurred following the progress of clinical symptoms. Five patients had laughter-cataplexy. MRI showed mild brain atrophy in 6 patients. Reduction of total cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol occurred in 6 patients. Sea-blue cells and Niemann-Pick cells were found in bone marrow smears. The activity of acid sphingomyelin enzyme was normal or only slightly lower. Supporting or symptomatic treatment improved common clinical symptoms. NP-C is a rare autosomal recessive inherited lysosomal storage disease that affects the intellectual development of children and may lead to dementia, vegetative state or death. Clinical features of this disease include vertical supranuclear gaze palsy, seizures and cataplexy. Laboratory features include abnormal plasma cholesterol level, and sea-blue cells and Niemann-Pick cells in bone marrow smears. The treatments of the disease include supporting or symptomatic administration.
    Article · Jun 2011 · World Journal of Pediatrics
  • Guang-na Cao · Xin-hua Bao · Hong-mei Lu · [...] · Xi-ru Wu
    [Show abstract] [Hide abstract] ABSTRACT: To understand the clinical and genetic features of Huntington disease (HD). The clinical data of HD cases from 2 Chinese families were analyzed and trinucleotide repeat in the IT15 gene were investigated in 9 of the two families by polymerase chain reaction and GeneScan. Among the two pedigrees, 6 cases were ascertained as HD by genetic test. Genotypes of IT15 were heterozygous in these HD patients. CAG repeat of the patients in the HD chromosome were 40-78. In the two pedigrees, the onset age was earlier in the subsequent generations than that of their fathers. In pedigree 2, the onset age was inversely correlated with CAG repeat number. One out of the 6 cases was juvenile-onset type of Huntington disease, whose clinical symptoms were different from those of the adult-onset cases, especially the hypertonic manifestation. HD is an autosomal dominant neurodegenerative disorder with genetic anticipation caused by enlargement of CAG repeat in IT15 gene. The clinical manifestation is different between the juvenile-onset and the adult-onset. The number of CAG repeat is inversely correlated with the onset age and clinical severity.
    Article · Apr 2011 · Beijing da xue xue bao. Yi xue ban = Journal of Peking University. Health sciences
  • [Show abstract] [Hide abstract] ABSTRACT: To evaluate the value of cryptococcal latex agglutination test in the diagnosis and treatment of cryptococcal meningitis in children. The clinical data of 10 children with cryptococcal meningitis were retrospectively studied. Cryptococcal meningitis was confirmed based on clinical manifestations, India ink stain, cryptococcal latex agglutination test or cryptococcal culture. The outcome of antifungal treatment and the changes of latex agglutination test titer were followed up for 2 to 4 years. Latex agglutination test and/or India ink stain were positive (titer 1 : 64-1 : 1024) in 8 patients in the first examination of cerebrospinal fluid. In the other 2 patients, latex agglutination test was positive (titer 1 : 256) in the fourth examination of cerebrospinal fluid in one, and India ink stain was positive in the eleventh examination in the other. After antifungal treatment, six patients were cured, two patients died, and two patients were lost to follow-up. The positive cryptococcal latex agglutination test (titer 1 : 2-1 : 16) was seen respectively in six, three, two and one cured patients 6 months, 1 year, 2 years and 4 years later. The cryptococcal latex agglutination test of cerebrospinal fluid is valuable for the quick and early diagnosis of cryptococcal meningitis; however, the decision of withdrawal of antifungal treatment should not rely on the results of the test.
    Article · Feb 2011 · Zhongguo dang dai er ke za zhi = Chinese journal of contemporary pediatrics
  • Jing-jing Zhang · Xin-hua Bao · Guang-na Cao · [...] · Xi-ru Wu
    [Show abstract] [Hide abstract] ABSTRACT: To identify the parental origin of methyl-CpG-binding protein 2 (MECP2) gene mutations in Chinese patients with Rett syndrome. Single nucleotide polymorphisms (SNPs) in intron 3 of the MECP2 gene were analyzed by PCR and sequencing in 115 patients with Rett syndrome. Then sequencing of the SNP region was performed for the fathers of the patients who had at least one SNP, to determine which allele was from the father. Then allele-specific PCR was performed and the products were sequenced to see whether the allele from father or mother harbored the mutation. Seventy-six of the 115 patients had at least one SNP. Three hot SNPs were found in these patients. They were: IVS3+22C >G, IVS3+266C >T and IVS3+683C>T. Among the 76 cases, 73 had a paternal origin of MECP2 mutations, and the other 3 had a maternal origin. There were multiple types of MECP2 mutation of the paternal origin, including 4 frame shift, 2 deletion and 67 point (56C >T, 6C >G, 2A >G, 2G >T and 1A >T) mutations. The mutation types of the 3 patients with maternal origin included 2 frame shift and 1 point (C >T) mutation. In Chinese RTT patients, the MECP2 mutations are mostly of paternal origin.
    Article · Apr 2010 · Zhonghua yi xue yi chuan xue za zhi = Zhonghua yixue yichuanxue zazhi = Chinese journal of medical genetics
  • Jing-jing Zhang · Xin-hua Bao
    [Show abstract] [Hide abstract] ABSTRACT: Rett syndrome (RTT), an X-linked dominant neurodevelopmental disorder characterized by regression of language, stereotype hand movement and loss of purposeful hand use, is primarily caused by mutation of menthyl-CpG-binding protein 2 (MECP2). The 76 kb human MECP2 is characterized by three salient features: a very large intron 2 (60 kb), an 8.5 kb 3'-UTR with highly conserved regions and different polyadenylation sites, and a 40 kb intergenic region separating MECP2 from the nearest upstream gene. There are two isoforms of MeCP2, MeCP2e1 and MeCP2e2. The differences between the two isoforms, the function of the 3'-UTR and the long-range cis-regulatory sequences in the intergenic region were extensively studied. In contrast to initial report, recent studies show that MeCP2 binds not only to methylated promoters and silence transcription, but also to the sites outside of genes containing only a few of CpG islands. Furthermore, MeCP2 can function as both an activator and a repressor of transcription.
    Article · Dec 2009 · Beijing da xue xue bao. Yi xue ban = Journal of Peking University. Health sciences
  • [Show abstract] [Hide abstract] ABSTRACT: To study the rate of subtelomeric rearrangements in patients with idiopathic mental retardation (MR) and to search the cause of MR. DNA was extracted and purified from peripheral blood leukocytes of 180 patients with idiopathic MR. DNA was tested using specific subtelomeric multiplex ligation-dependent probe amplification (MLPA) kits P036B/C and P070 according to manufacturer's instructions. The amplification products were separated by capillary electrophoresis using an ABI 3100 automated sequencer and size standard. MLPA data were extracted by GeneScan Analysis software. Data normalization and analysis were performed with the built-in MLPA application in GeneMarker. Among 180 patients with idiopathic MR, 12 had pathological subtelomeric deletions including 3 cases with a 4p deletion, 2 cases with a deletion at 9q and 22q respectively, 1 case with a deletion at 1p, 7p, 8p, 9q and 12q respectively. Subtelomeric rearrangements were responsible for 7% cases of idiopathic mental retardation. Subtelomeric rearrangement is a common cause of idiopathic mental retardation.
    Article · Nov 2009 · Zhonghua yi xue za zhi
  • [Show abstract] [Hide abstract] ABSTRACT: Rett syndrome (RTT) is a neurodevelopmental disorder occurring almost exclusively in females as sporadic cases due to de novo mutations in the methyl-CpG-binding protein 2 gene (MECP2). Familial cases of RTT are rare and are due to X-chromosomal inheritance from a carrier mother. Recently, DNA mutations in the MECP2 have been detected in approximately 84.7% of patients with RTT in China. To explain the sex-limited expression of RTT, it has been suggested that de novo X-linked mutations occur exclusively in male germ cells resulting therefore only in affected daughters. To test this hypothesis, we have analyzed the parental origin of mutations and the XCI status in 15 sporadic cases with RTT due to MECP2 molecular defects. Allele-specific PCR was performed to amplify a fragment including the position of the mutation. The allele-specific PCR products were sequenced to determine which haplotype contained the mutation. It was then possible to determine the parent of origin by genotyping the single nucleotide polymorphism (SNP) in the parents. The degree of XCI and its direction relative to the X chromosome parent of origin were measured in DNA prepared from peripheral blood leucocytes by analyzing CAG repeat polymorphism in the androgen receptor gene (AR). Except for 2 cases who had a frameshift mutation; all the remaining 13 cases had a C-->T transition mutation. Paternal origin has been determined in all cases with the C-->T transition mutation. For the two frameshift mutations, paternal origin has been determined in one case and maternal origin in the other. The frequency of male germ-line transmission in mutations is 93.3%. Except for 2 cases who were homozygotic at the AR locus, of the remaining 13 cases, 8 cases had a random XCI pattern; the other five cases had a skewed XCI pattern and they favor expression of the maternal origin allele. De novo mutations in sporadic RTT occur almost exclusively on the paternally derived X chromosome and that this is most probably the cause for the high female: male ratio observed in sporadic cases with RTT. Random XCI was the main XCI pattern in sporadic RTT patients. The priority inactive X chromosome was mainly of paternal origin.
    Article · Aug 2009 · Zhonghua er ke za zhi. Chinese journal of pediatrics
  • Mei-rong Li · Hong Pan · Xin-hua Bao · [...] · Xi-ru Wu
    [Show abstract] [Hide abstract] ABSTRACT: Rett syndrome (RTT) is a neurodevelopmental disorder that represents one of the most common genetic causes of mental retardation in girls. The aim of this study was to investigate the correlation between MECP2 genotype and phenotype and thereby not only to provide assistance for clinical care, but also facilitate clinical genetic counseling. Individual phenotype characteristic and clinical severity of 126 children with RTT diagnosed by molecular genetic methods were evaluated by using scales of Kerr et al and Scala et al. Statistical package SPSS 12.0 was used for analyses of data. Since the majority of the data were not normally distributed, non-parametric tests were used. The Kruskal-Wallis test/Wilcoxon Mann-Whitney test was employed to compare total severity phenotype scores. The Fisher exact test was used for comparing rates. Statistical significance was set at P < 0.05. There were no significant differences in the average overall scores for RTT patients with mutations in the region of methyl-CpG-binding domain (MBD) compared with those mutations in the transcription repression domain (TRD) and C terminal segment (CTS), also patients with nonsense mutations compared with missense mutations, frameshift mutations and large deletions (P > 0.05). The RTT patients with nonsense mutations located in the region of MBD have more severe phenotype than those with missense mutations in the same region (P = 0.016). Among p.T158M, p.R168X, c.806delG and p.R255X, there were no significant differences in the average overall scores (P > 0.05), but there were significant differences in language skill (P = 0.028) and in language impairment rate at different level (P = 0.019). There are relationships between MECP2 genotype and phenotype:the RTT patients with nonsense mutations located in MBD tend to develop more severe phenotype;there are significant differences in language skill and language impairment rate in the groups with p.T158M, p.R168X, c.806del and p.R255X, which had higher frequency in children below five-years of age and the p.R168X present with most severe impairment.
    Article · Mar 2009 · Zhonghua er ke za zhi. Chinese journal of pediatrics
  • Mei-rong Li · Hong Pan · Xin-hua Bao · [...] · Xi-ru Wu
    [Show abstract] [Hide abstract] ABSTRACT: To study the spectrum of mutations in methyl-CpG-binding protein 2 gene (MECP2) and cyclin-dependent kinase-like 5 gene (CDKL5) in Chinese pediatric patients with Rett syndrome (RTT), and establish a simple, quick, and efficient gene test method as well as screen a strategy of genetic diagnosis for RTT. Genomic DNA was extracted using standard procedures from the peripheral blood leukocytes of 117 pediatric patients diagnosed from 1987 to 2007. PCR was used to amplify the exons 1 - 4 of MECP2 using published primers. If no mutation was identified after screening exons 2 - 4, exon 1 was screened. If no mutation was identified in MECP2 by sequencing, multiplex ligation dependent probe amplification (MLPA) was employed to screen for large deletions by using P015C kit. If no mutation was identified in the MECP2 by sequencing and MLPA respectively, then the coding region of CDKL5 was screened by denaturing high performance liquid chromatography (DHPLC). The total mutation frequency in MECP2 and CDKL5 genes among all RTT patients was 82%. MECP2 mutations were found in 86% (137/159) of the patients with classical RTT and in 44% (8/18) of those with atypical RTT. Most of the mutations were missense mutations, accounting for 39%, followed in order of frequency by nonsense mutations 28%, frame shift mutations 17% and large deletions 14.5%. The eight most frequent MECP2 mutations were p.T158M (13%), p.R168X (12%), c.806delG (7%), p.R255X (6%), p.R270X (5%), p.R133C (5%), p.R306C (4%), and p.R106W (3%), with p.T158M as the most common of the MECP2 mutations and c.806delG as a hotspot mutation in Chinese patients with RTT. Only one synonymous mutation was identified in CDKL5. The spectrum of MECP2 mutations within the mainland Chinese RTT patients is similar to that of those patients reported in the world. p.T158M, p.R168X, c.806delG, p.R255X, p.R270X, p.R133C, p.R306C, and p.R106W are the hotspot mutations of MECP2 and c.806delG is a specific hotspot mutation in Chinese patients with RTT. The most effective method to screen mutations is to screen the exon 4. MLPA is an effective supplement to the routine methods.
    Article · Mar 2009 · Zhonghua yi xue za zhi
  • [Show abstract] [Hide abstract] ABSTRACT: To investigate the clinical, neurophysiologic characteristics and therapeutic considerations of epileptic negative myoclonus (ENM) in atypical benign partial epilepsy of childhood (ABPE). Video-EEG monitoring with outstretched arm tests were carried out in 17 patients, and 9 of them were examined with simultaneous electromyography (EMG). The ENM manifestations, electrophysiologic features and responses to antiepileptic drugs (AED) were analyzed. Seventeen patients were diagnosed as having benign childhood epilepsy with centrotemporal spikes (BECT) during the early course of the disease and were treated with AED. During the course of the disease, hand trembling, objects dropping, head nodding and instability during standing might be clues for ENM occurrence. ENM had been confirmed in our patients by outstretched arm tests during video-EEG recording. The ictal EEG showed that high-amplitude spikes followed by a slow wave over the contralateral motor areas. This was further confirmed by time-locked silent EMG in 9 patients. During ENM occurrence or recurrence, the habitual seizures and interictal discharges were exaggerated. Atypical absence seizures also occurred in 6 patients. The alteration of therapeutic options of AED relating to ENM appearance in some patients included the add-on therapy with carbamazepine (CBZ), oxcarbazepine, phenobarbital, or withdrawal of valproate (VPA). ENM was controlled in most cases by using VPA, clonazepam (CZP) and corticosteroid with different combination. ENM could occur during the course of ABPE. Outstretching arm tests during video-EEG monitoring in combination with EMG was essential to confirm ENM. The ENM occurrence was always associated with the frequency increasing of habitual seizures and the aggravation of interictal discharges. Some AED such as CBZ might induce ENM. VPA, benzodiazepines and corticosteroid with different combination were relatively effective in treatment of ENM.
    Article · Jan 2009 · Zhonghua er ke za zhi. Chinese journal of pediatrics
  • [Show abstract] [Hide abstract] ABSTRACT: To verify the sensitivity and reliability of methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) and to develop a simple, accurate, reliability method of genetic diagnosis for AS and PWS. Peripheral blood samples were collected from 4 suspected AS patients, 2 suspected PWS patients, 2 normal persons, and 2 molecular biologically proven positive controls (1 AS patient and 1 PWS patient). DNA was extracted and purified. MS-MLPA was used to detect the methylation of the CpG dinucleotide and the copy number in the 15q-q13 region. The results of MS-MLPA were confirmed by MSP. Three cases with maternal deletion on 15q11-q13 region and one case with paternal uniparental disomy (UPD) or imprinting center defect in 15q11-q13 region were found in the 4 suspected AS patients. One PWS case was found to be with paternal deletion in 15q11-q13 region and the other with paternal deletion in 15q11-q13 region or UPD or imprinting center defect in 15q11-q13 region. MS-MLPA is a simple, rapid, accurate, and reliable method of genetic test.
    Article · Jan 2009 · Zhonghua yi xue za zhi
  • Hong-mei Lu · Xin-hua Bao · Guang-na Cao
    Article · Sep 2008 · Zhonghua er ke za zhi. Chinese journal of pediatrics
  • [Show abstract] [Hide abstract] ABSTRACT: Clinical manifestations of opsoclonus-myoclonus syndrome (OMS) in children were summarized and analyzed and the clinical features and therapeutic approaches to OMS were investigated in order to improve its diagnosis and management. Clinical information on features and management of 6 cases with OMS inpatients being followed up from 2006 to 2007 were collected and analyzed. Among the 6 cases, one was male and the other five were female. The age at the onset ranged from 12 to 26 months (average 21.0 months). Four of them had history of prior infection. The symptoms were opsoclonus, myoclonus, ataxia, sleep disturbances and behavioural problems in the 6 cases. Urinary DL-3-methoxy-4-hydroxy-acid amygdalin (VMA) was positive in 1 case. Abdominal B-mode ultrasound showed a mild hepatomegaly in 4 cases. The EEG showed abnormal findings such as slow background activity in 3 cases. Epileptiform discharges were found in none of the patients. MRI showed a high signal in medial longitudinal fasciculus and tectospinal tract on T2-weighted image in 1 case. Computerized tomography found L3-4 arachnoid cysts in 1 case and was normal in the others. Adrenocorticotropic hormone (ACTH) was given to all these patients and was effective in all during acute stage. In 2 cases the disease relapsed during follow-up stage. OMS is a rare neurological condition with opsoclonus, myoclonus, ataxia, sleep disturbances and behavioral problems, which might relapse easily and is associated with adverse neurological outcome. ACTH therapy is effective in management of OMS.
    Article · Sep 2008 · Zhonghua er ke za zhi. Chinese journal of pediatrics