Clinical, pathological and molecular biological characteristics of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episode in children / 中华儿科杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHOD</b>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.</p><p><b>RESULT</b>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.</p><p><b>CONCLUSION</b>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.</p>

Clinical and genetic characteristics of glucose transporter type 1 deficiency syndrome / 中华儿科杂志

<p><b>OBJECTIVE</b>To analyze the clinical and SLC2A1 gene mutation characteristics of glucose transporter type 1 deficiency syndrome.</p><p><b>METHOD</b>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).</p><p><b>RESULT</b>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.</p><p><b>CONCLUSION</b>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.</p>

Genetic and phenotypic characteristics of SCN1A mutations in Dravet syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study SCN1A gene mutations and their inheritance in patients with Dravet syndrome(DS), and to analyze the phenotypes of their family members and genotype-phenotype correlations.</p><p><b>METHODS</b>Genomic DNA was extracted from peripheral blood samples from 181 DS patients and their parents. Phenotypes of affected members were analyzed. SCN1A gene mutations were screened using PCR-DNA sequencing and multiplex ligation-dependent probe amplification (MLPA) RESULTS: SCN1A gene mutations were identified in 128 patients (70.7%), which included 60 missense mutations (46.9%), 55 truncation mutations (43.0%), 10 splice site mutations (7.8%), and 3 cases with SCN1A gene fragment deletions or duplications(2.3%). Five patients (3.9%) had mutations inherited from one of their parents. One father has carried a somatic mutation mosaicism (C373fsx378). For the 5 parents carrying a mutation, 1 had febrile seizures, 2 had febrile seizures plus, 1 had afebrile generalized tonic-clonic seizures, whilst 1 was normal.</p><p><b>CONCLUSION</b>The mutation rate of SCN1A in DS patients is about 70%. Most mutations are of missense and truncation mutations. Only a few patients have carried fragment deletions or duplications. Most SCN1A mutations are de novo, only a few were inherited from the parents. SCN1A mutations carried by the parents can be in the form of mosaicism. The phenotypes of parents with SCN1A mutations are either mild or normal.</p>

Phenotype and SCN1A gene mutation screening in 39 families with generalized epilepsy with febrile seizures plus / 中华儿科杂志

<p><b>OBJECTIVE</b>To summarize the phenotypes and identify SCN1A mutations in families with generalized epilepsy with febrile seizures plus (GEFS(+)), and analyze the genotype- phenotype correlations in GEFS(+) families.</p><p><b>METHOD</b>Genomic DNA was extracted from peripheral blood lymphocytes of the proband and other available members in the GEFS(+) families. The phenotypes of the affected members were analyzed. The coding regions and flanking intronic regions of the SCN1A gene were screened for mutations using PCR and direct DNA sequencing.</p><p><b>RESULT</b>In 39 GEFS(+) families, there were 196 affected members, ranging from 2 to 22 affected members in each family. Their phenotypes included febrile seizures (FS) in 92(46.9%), febrile seizures plus (FS(+)) in 62(31.6%), FS or FS(+) with partial seizures in 12(6.1%), afebrile generalized tonic-clonic seizures (AGTCS) in 11(5.6%), myoclonic atonic epilepsy in 8(4.1%), Dravet syndrome in 2(1.0%), childhood absence epilepsy in 1 (0.5%), FS(+) with myoclonic seizures in 1(0.5%), AGTCS and myoclonic seizures in 1 (0.5%), partial seizures in 1 (0.5%), unclassified seizures in 5 (2.6%). Four families were found with SCN1A mutations, including three families with missense mutation (N935H, R101Q, G1382R) and one family with truncation mutation (C373fsx378). In three families with missense mutations, the phenotypes include FS, FS(+), FS(+) with partial seizures, and AGTCS. In one family with truncation mutation, the phenotypes included FS, FS(+), and Dravet syndrome. The mother of proband in the family with missense mutation (R101Q) and the father of proband in the family with truncation mutation (C373fsx378) were both somatic mosaicism. Both of their phenotypes were FS(+).</p><p><b>CONCLUSION</b>The most common phenotypes of GEFS(+) were FS and FS(+), followed by the FS/FS(+) with partial seizures and AGTCS. The most severe phenotype was Dravet syndrome. SCN1A mutation rate in GEFS(+) was about 10%. Missense mutation was common in GEFS(+) families, few with truncation mutation. Few members of GEFS(+) families had somatic mosaicism of SCN1A mutations and their phenotypes were relatively mild.</p>

Analysis of HEPACAM mutations in a Chinese family with megalencephalic leukoencephalopathy with subcortical cysts / 中华儿科杂志

<p><b>OBJECTIVE</b>To explore HEPACAM mutations in a Chinese family with megalencephalic leukoencephaloptathy with subcortical cysts (MLC).</p><p><b>METHOD</b>Genomic DNA samples were extracted from peripheral blood of the proband and her parents. All exons and exon-intron boundaries of HEPACAM and MLC1 were amplified in the MLC family by polymerase chain reaction (PCR) followed by direct DNA sequencing.</p><p><b>RESULT</b>Two heterozygous mutations of HEPACAM located in exon 2, c.203A > T(p.K68M) and c.395C > A(p.T132N), were identified in the proband. The proband's mother had the heterozygous mutations c.203A > T(p.K68M), and her father had the heterozygous mutation-c.395C > A(p.T132N). There was no variation found in MLC1 gene.</p><p><b>CONCLUSION</b>The proband was heterozygous compound MLC patient carrying on one allele with the c.203A > T(p.K68M) mutation inherited from her mother, and the other allele with the c.395C > A(p.T132N) mutation inherited from her father. The parents both are heterozygous carriers with normal phenotype. The disease-causing gene for this family was resulted in HEPACAM mutation other than MLC1 mutation.</p>

Clinical and genetic study of twelve Chinese patients with Alexander disease / 中华儿科杂志

<p><b>OBJECTIVE</b>To delineate the phenotype and genotype characteristics in 12 Chinese children with Alexander disease (AD), which is helpful for the molecular diagnosis and genetic counseling in China.</p><p><b>METHODS</b>Clinical diagnosis of AD was based on MRI criteria proposed by van der Knaarp in 2001. Included AD patients were followed up for 0.50 - 3.67 years. Mutations in GFAP were detected by DNA sequencing.</p><p><b>RESULTS</b>The 12 cases of AD were clinically diagnosed. Age of first visit was 4.87 years (0.75 - 12.00 years), with 3 types of chief complaints: developmental delay in 3, recurrent seizures in 7, unable to walk after falling in 2. Average head circumference was 52.34 cm (44 - 58 cm), which larger than age-matched average by 6.45% (1.80% - 13.95%). On the first visit, scaling according to Gross motor functional classification system (GMFCS) was performed, with GMFCSI in 8, II in 3, V in 1. Mild to severe cognitive dysfunction were found in 8, and seizures in 11 cases. The 12 patients were followed up for 0.50 - 3.67 years, their motor and cognitive function remained stable. Episodic aggravations provoked by fever or falling were observed in 5 cases (41.67%). Heterozygous missense mutations of GFAP were detected in 12 patients. All mutations were de novo; 3 out of 10 mutations identified were novel. R79 and R239 were hot mutations, which was consistent with previous reports. Mutations were located in exon 1 in 8 cases.</p><p><b>CONCLUSIONS</b>The phenotype in these patients is characterized by slower progression compared with reports from other population and high incidence of seizures. And episodic aggravations provoked by fever or falling were more common. The genotype characteristics are consistent with previous reports. The results of this research expanded the number of patients with Alexander disease found to have GFAP coding mutations in China.</p>

Association of genetic polymorphisms in methionine metabolism genes with X-linked adrenoleukodystrophy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the association of the polymorphisms of methionine metabolism genes and the phenotype of X-linked adrenoleukodystrophy (X-ALD) and clinical severity.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>The GG genotype of TC2 c.776 C/G may contribute to X-ALD phenotype.</p>

Clinical and mutation analysis of a Chinese family with muscle eye brain disease / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the clinical feature of a Chinese family with muscle-eye-brain disease (MEB) and the mutation of protein O-linked-mannose beta-1, 2-N-acetylglucosaminyltransferase 1 gene (POMGNT1).</p><p><b>METHODS</b>Clinical data of the proband and his family members were collected. Genomic DNA from the patient and his parents was extracted using standard procedures from the peripheral blood leukocytes. Polymerase chain reaction and DNA direct sequencing were employed to analyze all of the exons to determine the mutation, and the relationship between genotype and phenotype was analyzed.</p><p><b>RESULTS</b>The proband was diagnosed as floppy baby, presented with delayed psychomotor development and myopathic face. His serum creatine kinase (CK) level elevated moderately and brain MRI showed cerebral and cerebellar gyrus abnormalities with white matter signal intensity changes, cerebellar cysts and cerebellar and brain stem hypoplasia, consistent with congenital muscular dystrophy with eye brain disorder. Further test with DNA detected a compound heterozygous mutation of c.1896 1 G to C before exon 22 which may induce splicing error, and missense mutation c.1319T to G, p.L440R in exon 16. Both parents had a heterozygous mutation at the mutation sites.</p><p><b>CONCLUSION</b>According to our study, the family is diagnosed as MEB. The proband carried compound heterozygous mutations in the POMGNT1 gene, and his parents are heterozygous carriers, which is consistent with autosomal recessive inheritance. The child is definitely diagnosed as having muscle eye brain disease.</p>

Electroclinical features of myoclonic-atonic epilepsy / 中华儿科杂志

<p><b>OBJECTIVE</b>To summarize the electroclinical characteristics of myoclonic atonic epilepsy (MAE) in children.</p><p><b>METHOD</b>The clinical data, video electroencephalogram (EEG) and simultaneous electromyography (EMG) of MAE patients were analyzed. The treatment and its effects were followed up.</p><p><b>RESULT</b>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.</p><p><b>CONCLUSION</b>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.</p>

Analysis of the parental origin of MECP2 mutations in patients with Rett syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify the parental origin of methyl-CpG-binding protein 2 (MECP2) gene mutations in Chinese patients with Rett syndrome.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>In Chinese RTT patients, the MECP2 mutations are mostly of paternal origin.</p>

Correlation between MECP2 genotype and phenotype in Chinese patients with Rett syndrome / 中华儿科杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHOD</b>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.</p><p><b>RESULT</b>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).</p><p><b>CONCLUSION</b>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.</p>

Analysis of the parental origin of de novo MECP2 mutations and X chromosome inactivation in fifteen sporadic cases with Rett syndrome / 中华儿科杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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).</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

A case of Leigh syndrome associated with respiratory chain complex I deficiency due to mitochondrial gene 13513G>A mutation / 中国当代儿科杂志

Leigh syndrome is a genetically heterogeneous disease caused by defects in enzymes involved in aerobic energy metabolism and the Krebs', cycle. Mitonchondrial complex I deficiency is a main cause of Leigh syndrome. In this study, a Chinese child with Leigh syndrome caused by 13513G>A mutation was reported. The proband was the first child of his parents. The previously healthy boy presented with generalized epilepsy at 12 years of age. When he visited Peking University First Hospital at 13 years of age, he had subacute loss of vision in two eyes and temporal defect of visual field in the left eye. He walked with a spastic gait. His blood lactate and pyruvate levels were elevated. Muscle biopsy showed mild lipid accumulation in muscle fiber. An electrocardiogram showed incomplete right bundle branch block. Brain magnetic resonance imaging showed bilateral, symmetrical lesions in the basal ganglia, supporting the diagnosis of Leigh syndrome. 13513G>A mutation was identified by gene analysis in the patient, which led to mitochondrial respiratory chain complex I deficiency. Multivitamins and L-carnitine were administered. At present, the patient is 16 years old and has progressive deterioration with significant muscle weakness and body weight loss. He is absent from school. He has no obvious retardation in intelligence. 13513G>A mutation was first identified by gene analysis in Chinese population with Leigh syndrome. This may be helpful in genetic counseling.

Clinical features and SCN1A gene mutation analysis of severe myoclonic epilepsy of infancy / 中华儿科杂志

<p><b>OBJECTIVE</b>Severe myoclonic epilepsy of infancy (SMEI), or Dravet syndrome, is a severe epileptic encephalopathy. This study aimed to investigate the clinical features and genetic diagnosis of SMEI.</p><p><b>METHODS</b>The electroclinical data and the mutation of SCN1A gene in 13 children with SMEI were analyzed.</p><p><b>RESULTS</b>Of the 13 children, 10 were males and 3 were females. Eight of them had family history of febrile seizures. The average age of seizure onset was 5.6 months, with a range of 2 to 9 months. The initial seizure was a febrile seizure in 9 patients (69%). Generalized or hemiclonic seizures were often triggered by fever. Eight patients had a history of febrile status. Afebrile seizures occurred from 2 months to 21 months of age. All patients went on to develop multiple seizure types. Generalized tonic clonus seizures (GTCS) were found in 11, partial seizures in 12, atypical absence in 10. Myoclonic seizures were presented in all patients. Twelve patients had 3 or more seizure types. Seizures of all patients had a characteristic of temperature sensitivity. The precipitating factors included fever, hot bath and vaccination. Nine patients (69%) had a history of status epilepticus. Delay in mental development was present in 11 cases, ataxia in 5 and pyramidal sign in 2. EEG was normal in most patients in the first year of life, followed by generalized, focal and multifocal discharges. Brain MRI was abnormal in 2 cases. Seizures were not completely controlled in all patients. Carbamazepine and lamotrigine aggravated seizures in some patients. SCN1A gene mutation was found in 10 cases, including seven missense mutations, two nonsense mutations and one frame shift mutation.</p><p><b>CONCLUSION</b>The clinical features of SMEI were seizure onset within one year of age, first event is often a febrile seizure; multiple seizure types and mental delay occurred after the second year of life; seizures have a characteristic of temperature sensitivity; EEG was normal in the first year of life, followed by generalized, focal or multifocal discharges; early diagnosis by testing SCN1A mutation guides selection of antiepileptic drugs.</p>

Proteolipid protein 1 gene mutation in nine patients with Pelizaeus-Merzbacher disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Pelizaeus-Merzbacher disease (PMD) is a rare X-linked recessive disorder with symptoms including nystagmus, impaired motor development, ataxia, and progressive spasticity. The proteolipid protein 1 (PLP1) gene is the only pathogenic gene of PMD. Duplication of the PLP1 gene is the most frequent gene defect, accounting for 50%-70% of PMD cases, whereas point mutations in the coding sequence or the splice sites account for 10%-25% of PMD cases. This study aimed to identify PLP1 mutations in nine unrelated Chinese patients (P1-9) with PMD, and 14 subjects from the family of patient 2 were also described.</p><p><b>METHODS</b>Genomic DNA was extracted from peripheral blood samples. Gene dosage was determined using the multiplex ligation-dependent probe amplification (MLPA). All 7 exons and exon-intron boundaries of the PLP1 gene were amplified and analyzed using direct DNA sequencing.</p><p><b>RESULTS</b>Of these nine patients, there were four transitional, four classical, and one connatal PMD according to their clinical and radiological presentations. PLP1 duplications were identified in patients 1-7 with PMD. Their mothers were PLP1 duplications carriers as well. Both duplication carriers and normal genotypes of PLP1 were identified in the family members of patient 2. A c.517C > T (p. P173S) hemizygous missense mutation in exon 4 was found in patient 8 with PMD, and his mother was shown to be a heterozygote of this mutation.</p><p><b>CONCLUSIONS</b>We identified seven genomic duplications and one missense mutation (p. P173S) of the PLP1 gene in eight Chinese patients with PMD. This is the report about PLP1 mutations in PMD patients from the mainland of China.</p>

Leigh syndrome due to pyruvate dehydrogenase E1 alpha subunit gene mutation: a complicated and difficult case study / 中国当代儿科杂志

Leigh syndrome is a genetically heterogeneous disease caused by defects in enzymes involved in aerobic energy metabolism and the Krebs' cycle. Deficiency of pyruvate dehydrogenase complex E1 alpha subunit (PDHA1) is the common cause of Leigh syndrome. In this study, one Chinese case of PDHA1 deficiency was reported. The patient was a boy with normal mental development, retarded motor development, general weakness, hypotonia and areflexia. Muscle histopathological findings suggested axonal peripheral neuropathy. Brain magnetic resonance imaging at 5 years of age revealed bilateral putamina lesions and periventricular white matter demyelination, supporting the diagnosis of Leigh syndrome. A C214T mutation in exon 3 of the PDHA1 gene was detected. After the treatment of thiamin, coenzyme Q10, Lcarnitine and carbohydrates-restricted diet, his movement ability improved significantly. At present, the patient is 8 years old and has normal school life. PDHA1 deficiency is an X-linked inherited metabolic disease, which shares various clinical manifestations and leads to difficult diagnosis. This patient predominately presented with progressive weakness and was diagnosed by gene analysis.

Clinical studies on fifty-seven Chinese patients with combined methylmalonic aciduria and homocysteinemia / 中华儿科杂志

<p><b>OBJECTIVE</b>Methylmalonic aciduria (MMA) is a common one of the congenital disorders of organic acids metabolism. Some of the patients with the disorder are complicated with homocysteinemia. Recently, gas chromatography-mass spectrometry (GCMS) has been used to diagnose MMA in China. However, the diagnosis of the patients with combined MMA and homocysteinemia is often delayed. In this study, the natural history, clinical features and outcome of 57 Chinese patients with combined MMA and homocysteinemia were investigated.</p><p><b>METHODS</b>From 1996 to 2006, 96 MMA patients from 16 provinces or cities were diagnosed in our hospital by urine organic acids analysis using GCMS. Homocysteinemia was found by serum and urine total homocysteine determination using a fluorescence polarization immunoassay.</p><p><b>RESULTS</b>Fifty-seven of the 96 MMA patients (59.4%, 32 males and 25 females) were found to have combined MMA and homocysteinemia. They had markedly increased urine methylmalonic acid, total serum homocysteine (81.5 to 226.5 micromol/L vs. normal range 4.5 to 12.4 micromol/L) and urine homocysteine (79.1 to 414.5 micromol/L vs. normal range 1.0 to 25.0 micromol/L). Thirteen (22.8%) of them presented with symptoms resembled hypoxic-ischemic encephalopathy in the neonatal period. Fourteen (24.6%) patients had the onset at the age of one month to 1 year with mental retardation, vomiting and epilepsy. Nine (15.8%) showed developmental delay, seizures, poor appetite or anemia from the age of 1 to 3 years. Eighteen (31.6%) had psycho-motor degeneration at the age of 6 to 15 years. Among them, 7 patients experienced multiple organ dysfunctions with liver dysfunction, hematuria, renal failure and peripheral neuropathy. Three (5.3%) patients developed progressive mental degeneration, motor disorders and anorexia at the ages of 16, 24 and 34 years. Eleven (19.3%) patients ultimately died; 5 (8.8%) of them were diagnosed postmortem. Forty-six (80.7%) patients were treated with vitamin B12, folic acid, L-carnitine and betaine supplementation and 11 (19.3%) of them recovered completely.</p><p><b>CONCLUSIONS</b>Combined MMA with homocysteinemia is a common form of MMA in China. The clinical spectrum of the patients varies from severe neonatal-onset forms with high mortality to milder forms with adult-onset. Serum or urine total homocysteine analysis is important for the deferential diagnosis of the patients with MMA.</p>

Clinical features and management of multiple sclerosis in children / 中华儿科杂志

<p><b>OBJECTIVE</b>Multiple sclerosis is a demyelinating disease frequently showing a relapsing-remitting disease course. Clinical manifestations of 25 inpatients with MS were summarized and analyzed so that the clinical features and therapeutic approaches to childhood multiple sclerosis (MS) were investigated in order to improve its diagnosis and management.</p><p><b>METHODS</b>Clinical features and information during following-up of 25 cases with MS from June 1993 to May 2006 were collected and analyzed.</p><p><b>RESULTS</b>Among the 25 cases, 16 were female and the F:M ratio was 1.78:1. The relapsing-remitting type was seen in 21 cases, the secondary progressive MS in 3 cases and the classification was impossible in one case. The mean age of onset was 6.7 years (2-12) with various initial symptoms including visual loss (11 cases), cortical symptoms (8 cases with seizures, consciousness disturbance, aphasia and apraxia, etc.), myeleterosis (3 cases), symptoms of brainstem (2 cases) and cerebellar ataxia (1 case). Fever was present in 10 cases at the onset. Nine cases were monosymptomatic, while the other 16 had multiple symptoms. Visual loss occurred in 19 cases during the course of MS and 22 were found to have abnormal visual evoked potential (88%). The mean course of disease was 8.5 years (1.2-17.2) and 0-4 times of recurrences (0 means no new clinical attack occurred during following-up period).</p><p><b>CONCLUSIONS</b>MS is increasingly recognized as a disease affecting children though it is uncommon. Childhood MS possesses some manifestations different from those of adults. There was a female predominance. The most common finding at the onset of disease was optic neuritis. Other features include acute onset and shorter course of disease. Atypical demyelinating symptoms were often seen. White matter lesions on MRI are required for the diagnosis. CSF oligoclonal bands could be found less commonly than in adults. Neurological sequelae were less often seen than in adults MS even though optic nerve atrophy and visual loss were relatively common. Steroid and IVIG are effective in acute period treatment.</p>

Application of long range polymerase chain reaction and DNA direct sequencing in diagnosis of Rett syndrome / 中华儿科杂志

<p><b>OBJECTIVE</b>Rett syndrome (RTT, MIM 312750) is a progressive neurodevelopmental disorder that affects females almost exclusively, caused by mutations in MECP2 gene on chromosome Xq28, with symptoms such as autism, severe mental deficiency, deceleration of head growth, ataxia, loss of purposeful hand function and characteristic stereotypic hand movements. Over 80% MECP2 mutations located in the exon 3 and exon 4 were confirmed by our work and large-scale studies. RTT is defined based on clinical presentation. It is difficult to diagnose in the early life without definite biochemical abnormality, but genetic test is helpful for this. The aim of this study was to investigate the feasibility and clinical significance of applying long range polymerase chain reaction (PCR) to RTT diagnosis and establish a simple, economic, efficient method of genetic diagnosis.</p><p><b>METHOD</b>Genomic DNA was extracted using standard procedures from the peripheral blood leukocytes of each patient. Long range polymerase chain reaction(PCR)and DNA direct sequencing were employed to analyze the exon 3 and 4 of MECP2 gene simultaneity in 40 patients with RTT. The PCR products were checked by using 1.5% agarose gel.</p><p><b>RESULT</b>In total, 18 different MECP2 mutations were identified in 33 of the 40 diagnosed sporadic female patients with RTT. Missense mutations were 16, followed by 14 nonsense mutations and 3 deletions. The 314 base pairs large deletion was identified. The p. T158M mutation (21%, 7/33) was the most common, followed in order of frequency by p. R255X (12%, 4/33), p. R168X and p. R106W (9%, 3/33) respectively, p. R270X and p. Y141X (6%, 2/33) respectively, p. R133C, p. D156H, p. P157L, p. P225R, p. Q244X, p. Q262X, p. R294X, p. R306C, P322L, c. 1005del G, c.1005-1318del 314 bp and c.1127-1179del 53 bp (3%, 1/33), respectively.</p><p><b>CONCLUSION</b>Long range PCR is a simple, economic, quick, precise method of genetic diagnosis and was able to find 83% MECP2 gene mutations in RTT patients in this study. It is helpful for RTT clinical diagnosis in early stage. On the other hand, it may detect recurrent mutations and large deletions at the same time.</p>

Clinical characteristics and treatment of Rasmussen syndrome in 16 children / 中华儿科杂志

<p><b>OBJECTIVE</b>Rasmussen syndrome (RS) is a chronic inflammatory disease of unknown origin, usually affecting one brain hemisphere. The present study aimed to analyze the electroclinical characteristics and treatment of RS.</p><p><b>METHODS</b>The medical records of 16 children with RS were retrospectively reviewed.</p><p><b>RESULTS</b>Of the 16 children, 8 were males and 8 were females. The age of onset was from 1 year and 11 months to 11 years and 6 months. The first symptom was seizure in all patients. The main seizure type was partial motor seizures. In all the patients, seizures gradually became frequent and in the form of epilepsia partialis continua (EPC). Thirteen cases developed hemiparesis. Fixed hemiparesis occurred from 2 months to 3 years after the onset of seizures. The cognitive deterioration was present in 14. The EEG background activity was abnormal in all the cases, asymmetric slow wave disturbances were bilateral but with unilateral predominance in 11, unilateral delta or theta wave in 8. The presence of interictal epileptiform discharges were found in all cases, unilateral in 11 and bilateral in 5. Seizures were recorded in all patients, no electroclinical correlation was found in 5. Serial magnetic resonance imaging (MRI) showed progressive unihemispheric or focal cortical atrophy in all cases. Six cases transiently showed focal cortical swelling or T2/FLAIR hyperintense signal on early scans. Antiepileptic drugs were not effective in any of the patients. Three of 10 patients receiving immunoglobulin, and 4 of 8 receiving corticosteroids, had some reduction of seizure frequency for a short period. Six patients accepted functional hemispherectomy, in 4 of them seizure no longer occurred and cognitive function was improved. The results of multiple subpial transection in 2 cases and focal resection in one patient were disappointing.</p><p><b>CONCLUSION</b>The clinical features of RS were refractory partial epilepsy, progressive hemiplegia and cognitive deterioration. The EEG background was asymmetric with slow wave activity, interictal epileptiform discharges were unilateral or bilateral, no electroclinical correlation occurred. Serial MRI showed progressive unihemispheric focal cortical atrophy. Antiepileptic drugs were not effective for RS. In some patients, immunoglobulin or corticosteroids could reduce seizure frequency in the short term. Functional hemispherectomy could lead to seizure control and prevent further development of neurological impairment and cognitive deterioration.</p>