OBJECTIVE To analyze the prevalence of pathogens in liver abscess and their resistance.METHODS All specimens of liquor puris were collected from patients with liver abscess by liver puncture in Union hospital,Fujian Medical University from Jan 2002 to Dec 2007.Pathogens were isolated,and followed by antibiotics resistance assay.RESULTS The key pathogens of liver abscess were Gram-negative bacteria.The main Gram-negative bacteria were Escherichia coli and Klebsiella pneumoniae.The main Gram-positive bacteria were Streptococcus,Enterococcus and Staphylococcus.The resistance of K.pneumoniae was increased in recent years.CONCLUSIONS The bacterial species in the liver abscess are varying in recent six years,the ESBLs are the important factor of the resistance to antibiotics.

Objective To describe the MRI features of vanishing white matter disease (VWM).Methods Ten patients diagnosed as VWM between 2008-2013 were enrolled,with the mean age of(40 ±23)months.The clinical materials and MR images of them were reviewed retrospectively.The findings of MRI were analyzed by two experienced neuroradiologists in this study,including the location (cerebrum,cerebellum,brainstem,corpus callosum and internal/external capsule),size and signal intensity of the lesions,as well as the presence of cystic degeneration,cerebrum atrophy and the abnormal signal of the basal nuclei.Results MRI of brain typically showed extensive abnormal signal in the cerebral central white matter (10/10) and the focal lesion in subcortical white matter (9/10).The involvement of U-fibers was present in 7 cases.Cystic degeneration of the affected white matter was found in 7 cases.Abnormal signal also appeared in the white matter of posterior limb of the internal capsule (8/10),the external capsule (7/10),the inner rim (the callosal-septal interface) of the corpus callosum (8/10).The lesions of the thalamus and globus pallidus were detected in 2 cases.The white matter of the brainstem and cerebellum were involved in 6 and 7 cases respectively.Conclusion VWM typically shows a diffuse and symmetrical abnormal signal in the cerebral white matter with cystic degeneration on MRI,which is usually diagnostic.

Objective To analyze the clinical and MRI features of patients with type Ⅱ Alexander disease (AxD) in order to better understand and diagnose it earlier.Methods Four type Ⅱ AxD patients identified by glial fibrillary acidic protein gene mutations from Peking University First Hospital and 128 type Ⅱ AxD cases from published literatures were collected,and the clinical and MRI features were summarized.Results (1) In 4 type Ⅱ AxD patients,2 adult patients showed abnormal MRI features without clinical manifestation.The other 2 children patients both manifested motor dysfunction of lower limbs,pyramidal signs,paroxysmal deterioration,and seizures during the course of disease,while 1 of them had bulbar paralysis.The MRI of all the cases was abnormal,but only 1 case MRI corresponded with typical MRI features of type Ⅱ AxD.In the other 3 cases MRI showed thc atrophy in the medulla and upper spinal cord,or the brainstem lesions and abnormal signal in the periventricular white matter,and abnormal basal ganglia region.(2) In 128 reported type Ⅱ AxD cases,the age of onset was (32±19) years old.The initial syndromes mainly contained bulbar and/or pseudobulbar paralysis (32.48％,38/117 cases),motor dysfunction of the lower limbs (31.62％,37/117 cases) and autonomic nerve dysfunction (13.67％,16/117 cases).During the course of the disease,the clinical manifestation showed bulbar and/or pseudobulbar paralysis (73.50％,86/117 cases),pyramidal signs (60.68％,71/117 cases) and ataxia (51.28％,60/117 cases).The MRI of all cases was characterized by atrophy or abnormal signals in the brainstem,especially in medulla oblongata,and spinal cord.And abnormal signals in the cerebellar dentate nuclei,white matter,basal ganglia and thalamus were also commonly shown in the MRI.Conclusions The patients with type Ⅱ AxD are late-onsct.The clinical manifestation mainly contains bulbar and/or pseudobulbar paralysis,motor dysfunction of the lower limbs and pyramidal signs.The MRI is characterized by atrophy or abnormal signals in the brainstem (especially in medulla oblongata) and spinal cord.

Objective To summarize the phenotypic features of an unrecognized leukoencephalopathy in infants sharing same clinical features,and to better understand the disease and provide new evidence for identification of new leukoencephalopathy. Methods Clinical and follow-up data of 13 patients with unrecognized infantile leukoen-cephalopathy were collected from Peking University First Hospital from January, 2006 to December, 2014. Results (1) There were 7 male and 6 female. The average age of onset was 11 months (4-25 months). Thirty-eight percent (5/13 cases) of patients had incentives before the onset;all of the cases had acute onset and rapid motor function regression. Fifteen percent (2/13 cases) of the patients suffered from seizures in the course of the disease. Patients′condition became stable,and cognition and motor function improved gradually 1 month after onset. No patient died till the last follow-up. (2) Imaging features:magnetic resonance imaging (MRI) of the patients was characterized by im-plicating deep white matter,presenting T1 hypointense,T2 and fluid attenuated inversion recovery ( FLAIR) hyperin-tense in the periventricular area. All of MRI showed massive and symmetric lesions with heterogeneous signal and cystic degeneration. DWI showed patch or massive hyperintense in some of the lesions. The follow-up MRI showed the original lesions decreased in 88% ( 8/9 cases ) of patients, and white matters atrophied in 55% ( 5/9 cases ) of patients;the cystic degeneration still existed and even expanded;DWI showed regional linear or spot hyperintense in 88% (8/9 cases) of patients,which was smaller than before,and distributed around the original lesions. Conclusions The patients with leukoencephalopathy caused by unknown pathogenic gene were much likely to be mitochondrial leukoencephalopathy. This study provided evidence for further exploration of new pathogenic genes causing leu-koence-phalopathy.

Objective To estimate prenatal diagnoses strategy with abnormal results of non-invasive prenatal testing (NIPT) based on a case of mosaic for trisomy 22.Methods The pregnanct woman was recruited from Department of Prenatal Diagnosis Center of Xinhua Hospital.Ultrasound scans suggested fetal nuchal translucency was 3.5 mm.Peripheral venous blood was drawn from the pregnant woman for NIPT at 12+2 weeks gestation.For further prenatal diagnosis, amniocentesis was conducted at 16+2 weeks gestation, and karyotype analysis combination with chromosome microarray analysis (CMA) was executed to analysis amniocytes.Results NIPT results suggested that chromosome 21, 18 and 13 were normal and supplementary reports suggested that chromosome 22 were slightly above the normal range.Karyotype analyzed 35 cultured cells.Each of them revealed a normal female karyotype.However, CMA results suggested that chromosome 22 gain mosaic and its copy number was 2.26.The fetus was diagnosed as high possibility of mosaic for trisomy 22.Conclusions Combined with the NIPT results, which was slightly gain mosaic of chromosome 22, a prenatal diagnosis strategy were proposed.When NIPT results suggest chromosomal abnormities, karyotype analysis combination with CMA to diagnose were recommended.

Objective To investigate proteolipid protein 1 (PLP1) mutations in six pedigrees with Pelizaeus-Merzbacher disease (PMD),and to provide prenatal consulting and prenatal diagnosis.Methods Subjects were six probands with PMD admitted in Department of Pediatrics,Peking University First Hospital from July 2006 to November 2011 and their family members.Genomic DNA sarnples were extracted from peripheral bloods of probands and their family members.Multiplex ligation-dependent probe amplification (MLPA) technique was used to detect PLP1 duplication mutation.Direct DNA sequencing was used to detect point mutation.Genetic diagnosis were based on PLP1 mutation genotype from probands.Prenatal diagnosis of nine fetuses were performed from seven PLP1 mutation female carriers by fetuses' DNA extracted from amniocytes or villus cells.Results PLP1 duplications were found in probands 1-4 (P1-4) whose mothers and the aunt of proband 1 (P1) were PLP1 duplications carriers.The two cases of point mutation,c.96C＞G(p.F32L) and c.623G＞T (p.G208V),were found in proband 5 (P5) and proband 6 (P6).Hcterozygous changes of the same mutations were found in P5' and P6' mothers with normal phenotypes.Seven female PLP1 mutation carriers were pregnant again.Prenatal diagnosis of PLP1 for nine fetuses presented one PLP1 duplication,one point mutation,one PLP1 duplication carrier,and six wildtypes.A segmental crossing over of X chromosome was detected in one male fetus of PLP1 wildtype.Conclusions PLP1 mutation analysis could help to diagnose PMD pedigree and to identify female PLP1 mutation carrier in the family.The following prenatal diagnosis and proper genetic counseling are very important to prevent PMD child from being delivered.

Objective To analyze the clinical data and TUBB4A mutation of hypomyelination with atrophy of the basal ganglia and cerebellum (HABC)in a family,thus to provide accurate genetic counseling and prenatal diagno-sis for this family with HABC,and also to provide clinical experience for the diagnosis of HABC in China.Methods The clinical data of the proband and her family members were collected at the Department of Pediatrics,Peking Univer-sity First Hospital,December 201 4,including medical history,physical signs,and brain MRI,biochemical tests and metabolic disease screening.The associated gene of hereditary leukoencephalopathy was screened for the proband and her family members were screened by targeting -high -throughput sequencing technology,and then the genetic varia-tions were verified by Sanger sequencing.With those detection methods,the gene mutation was confirmed,and then ge-netic features were analyzed.Results Clinical features were as follows:nystagmus as the first symptom,and motor and mental retardation,dystonia and ataxia followed.Brain MRI indicated hypomyelination of white matter and atrophy of the basal ganglia and cerebellum.The clinical diagnosis of HABC was established based on the clinical features and brain MRI features above.Genetics features showed that one novel TUBB4A c.974G >T heterozygous missense muta-tion was found from the proband,which caused an amino acid change from the Trp into Leu (p.Trp325Leu).Both of her parents with normal phenotype were of wild -type in this site.Conclusions The proband from this family was diagnosed clinically based on her clinical data.One novel TUBB4Ac.974G > T (p.Trp325Leu)was founded in this study.Therefore,the spectrum of TUBB4A mutation will be expanded.In addition,this study elucidated clinical and genetic characteristics in this family with HABC,which may lay a solid foundation for the accurate genetic counseling and prenatal diagnosis.This study reported the first case of HABC caused by TUBB4A mutation in China.

Objectives To provide genetic counseling and prenatal molecular diagnosis for two families with megalencephalic leukoencephalopathy with subcortical cysts (MLC).Methods Two MLC patients (probands 1 and 2) were admitted to the Department of Pediatrics of Peking University First Hospital in June 2011 and June 2009,respectively.Peripheral blood was collected and DNA sequencing was performed for genetic analysis for the two MLC patients and their parents.Amniotic fluid and villus of two fetuses (fetus 1 and 2) were collected at 21+4 and 12+3 weeks of gestational age from their mothers when they were pregnant again.The genomic DNA of the two fetuses was extracted and corresponding sites of MLC1 gene were sequenced.Haplotype analysis using a combination of 3 microsatellite markers (AR,DXS6807 and DXS6797) on chromosome X and sex determining region of Y chromosome was performed to detect maternal cell contamination.Verification of the prenatal molecular diagnosis and follow up study after birth were conducted for both fetuses.Results Macrocephaly,motor development delay and typical findings on brain MRI were identified in the two probands,and were clinically diagnosed with MLC.Compound heterozygous mutations were detected in proband 1 [c.353C＞T (p.T118M) and c.803C＞G (p.T268R)] and proband 2 [c.353C＞T (p.T118M) and c.836T＞C(p.L279P)],respectively.MLC was genetically diagnosed.Heterozygous variation in c.353[c.353C＞T (p.T118M)] and wild c.803C were identified in fetus 1,and both wild c.353C and c.836T were found in fetus 2.No maternal cell contamination was detected in both fetuses.Sequencing the corresponding sites after birth confirmed the prenatal diagnosis,and the head circumference and motor development were normal in fetus 1 at 5 months old.No macrocephaly was found and no DNA sequencing was done in fetus 2 at one month old.Conclusions Genetic counseling and prenatal molecular diagnosis for MLC families combined with clinical and genetic diagnosis are important in preventing MLC.Haplotype analysis with a combination of three microsatellite markers on chromosome X and sex determining region of Y chromosome is useful in detecting maternal cell contamination and avoiding its influence on prenatal diagnosis,and confirming the reliability of prenatal diagnosis.

Objective: To summarize the clinical features of leukoencephalopathy with vanishing white matter disease (VWM) in children. Methods: A retrospective cohort study was performed on 54 genetically diagnosed VWM patients in Peking University First Hospital from January 2007 to March 2019. Paper registration form and electronic medical record system were used to collect the data,and the children were divided into five groups according to the age of disease onset:<1 year, 1-<2 years, 2-<4 years, 4-<8 years and 8-<18 years respectively. The progression of motor function, episodic aggravation, epileptic seizures, survival time, brain magnetic resonance imaging (MRI) and genotype features were analyzed and compared. Non-parametric test, χ² test or Fisher′s exact test were used for comparison among groups; Kaplan-Meier survival curve was adopted to delineate the survival status of the children. Results: Fifty-four VWM patients were included in the study, including 34 males and 20 females.The age of disease onset was 2 years and 8 months (ranged from 6 months to 9 years and 7 months). Onset age was less than 1 year in 5 cases; onset age was 1-<2 years in 12 cases; onset age was 2-<4 years in 25 cases; onset age was 4-<8 years, in 10 cases; onset age was 8-<18 years in 2 cases; 94% (51/54) of patients had complaint of motor regression at the first visit; 87% (47/54) of patients suffered from episodic aggravation. Episodic seizures occurred in 43% (23/54) patients. In survivors with disease durations of 1-3 years, in 38% (9/24) patients the disease was classified as grades Ⅳ-Ⅴ by gross motor function classification system (GMFCS). For the onset age 1-<2 years group, 1 patient was classified as GMFCS Ⅳ among 3 survivors with disease durations of 1-3 years. As for the 2-<4 years group, 6 patients were classified as GMFCS Ⅳ-Ⅴ among 15 patients with disease durations of 1-3 years, whereas 1 patient was classified as GMFCS Ⅳ-Ⅴ among 4 patients with disease durations of 1-3 years in the 4-<8 years group. Lesions, liquefaction and diffusion restriction in brain MRI were compared among different groups, and it was revealed that the earlier the age of disease onset was, the more likely the subcortical white matter (frontal lobe P<0.01,temporal and parieto-occipital lobe both P=0.002), internal capsule (anterior limb P<0.01, posterior limb P=0.00) and brain stem (midbrain P=0.001, pons P<0.01) were to be involved. In addition, internal capsule (anterior limb P=0.002, posterior limb P=0.005) and brain stem (midbrain P=0.001, pons P=0.003) showed more diffuse restricted diffusion. Moreover, the subcortical white matter (frontal and parieto-occipital lobe both P<0.01, temporal lobe P=0.005) showed earlier rarefaction. The 1-year and 2-year survival rates of the overall patients were 81% and 75% respectively, while the 15-year survival rate was 45%. EIF2B5 gene variation was the most common, which accounts for 43% (23/54), followed by EIF2B3 (22%, 12/54). Conclusions The majority of VWM patients complained of motor regression at the first visit, episodic aggravation and epileptic seizures are common in the course. Earlier age at onset is associated with more rapid clinical progression, shorter survival time as well as more extensive lesions, liquefaction and diffusion restriction in brain MRI. The most common variant gene is EIF2B5, followed by EIF2B3.

Objective: To identify the clinical and genetic characteristics in 43 Chinese children diagnosed with type Ⅰ Alexander disease (AxD). Method: Forty-three type Ⅰ AxD cases identified by glial fibrillary acidic protein (GFAP) gene mutations in Peking University First Hospital from 2005 to 2016 were followed up. The data of medical history, physical examination and magnetic resonance imaging (MRI) were collected. All these patients were followed up in December 2010, Febury 2012, June 2014 and January 2016, respectively. Result: Forty-three patients were genetically confirmed as type I AxD and the median age at the last visit was 11.71 years (10.27, 13.15). The characteristic clinical manifestations of these type Ⅰ AxD patients were developmental delay (79%, 34/43), seizures (86%, 37/43), macrocephaly (the median percentile of head circumference is 90%), and paroxysmal deterioration (27%, 13/43). All the 43 patients′ brain MRI satisfied typical MRI features proposed by van der Knaap. According to the analysis of the long-term follow-up, patients with type Ⅰ AxD began to have obvious regression in motor function after 7 years of age, and the social life ability was milally impaired 8(6, 10)scores at the last follow-up. Seventeen heterozygous missense mutations of GFAP were identified in 43 genetically confirmed patients, and 4 mutations were novel. The mutations in 41 patients (95%, 41/43) were de novo. Three hot spots of mutation in Chinese patients were found: p. Arg239(35%, 15/34), p. Arg79 (26%, 11/43) and p. R88 (16%, 7/43). Conclusion The characteristic clinical manifestations of type Ⅰ AxD patients are developmental delay, seizures, macrocephaly and paroxysmal deterioration. Moreover, a few patients may present with brain stem symptoms, mental abnormalities, scoliosis or kyphosis. Patients with type Ⅰ AxD may show significant regression in motor function after 7 years of age.