Objective To analyze the clinical and imaging features of 2 siblings with leukoencephalopathy due to NADH dehydrogenase (ubiquinone)flavoprotein 2 (NDUFV2) gene mutation,in order to better understand and diagnose it earlier.Methods Clinical and follow-up data of the proband and his brother were collected.Clinical features including symptoms,signs and cranial magnetic resonance imaging (MRI) were analyzed,and 2 patients were followed up for a long time.Sanger sequencing,targeted next generation sequencing,and whole exome sequencing were performed to identify potential genetic variations in the 2 patients and their parents.Results (1) Clinical characteristics and follow-up:ages of onset were 4 months and 1 year respectively.Both of the patients presented rapid motor regression hyperinyotonia,positive pathological character.During the follow-up the condition became stable,motor function and cognition improved gradually after cocktail therapy.(2) Brain MRI of the 2 patients showed prominent abnormalities in deep cerebral white matter,presenting T1 hypointense,T2 and fluid attenuated inversion recovery (FLAIR) hyperintense in the periventricular area.FLAIR images revealed that the abnormal white matter was partially rarefied and cavitated.Diffusion weighted images (DWI) showed high signals along the periphery of the involved areas.The follow-up MRI showed the cavitation still existed and even expanded,and DWI showed regional linear or spotty high signals around the original lesions.(3) Novel mutations in NDUFV2 gene,c.467T>A and c.404G>C,were identified in proband and his brother.The former inherited from his father,while the latter inherited from his mother,which was the new mutation not reported in the international.Conclusions The clinical features of the brothers presented subacute leukoencephalopathy with relatively stable or improved outcome.This was distinctive from the phenotypic features reported in 12 cases with hypertrophic cardiomyopathy or Leigh syndrome.The finding expanded the phenotypic spectrum of NDUFV2 mutations.Pathogenic gene of these patients which is the basis of genetic counseling for this family was determined.

Objective To study the association of vitamin D receptor(VDR) gene BsmI polymorphism and the genetic susceptibility of vitamin D deficiency rickets in infants and to explore a new way of diagnosis and treat-ment. Methods Case-control study was adopted. 56 infants confirmed with rickets (case group) and 76 cases of normal infants (control group) were chosen as the subjects. PCR-RFLP was applied to examine VDR gene BsmI site polymorphism. The frequencies of the VDR genotype and allele were compared between the two groups. Results Frequencies of BB,Bb and bb genotypes were 3.6% (2/56),21.4% (12/56) and 75.0% (42/56) in the rickets group,and 1.3% (1/76),18.4% (14/76) and 80.3% (61/76) in the control group respectively(χ20.521,P> 0.05),frequencies of B,b alleles were 14.3% (16/112),85.7% (96/112) in the rickets group and 10.5% (16/152),89.5% (134/152) in the control group respectively(χ20.783,P>0.05). Multiple logistic regression analysis showed that VDR gene polymorphism Bsml had not higher risk of vitamin D deficiency rickets in Infants. Conclusion VDR gene polymorphism BsmI doesn't appear to pose risk on infants in developing vitamin D deficien-cy rickets.

Objective To analyze the clinical and imaging characteristics of congenital sensorineural hearing loss (CSNHL)children combined with white matter (WM)lesions in order to provide evidence for clinical practice. Methods With referral to the Department of Pediatrics,Peking University First Hospital from November 201 1 to De-cember 201 5,documents of 78 patients of CSNHL combined with WMlesions were collected and analyzed for the clini-cal and imaging characteristics.Results Bilateral severe -profound hearing loss existed in all 78 cases,48.1 %(25 /52 cases)of the patients exhibited gross motor development delay,98.1 %(51 /52 cases)of them had normal cognition development.One hundred percent (61 /61 cases)of patients had abnormal language development.Infection occurring during pregnancy existed in 21 .2%(1 1 /52 cases)of the patients,the premature and smaller for the gestational age in-fants accounted for 28.9% (1 5 /52 cases).The bilateral multiple WMlesions from the brain MRI were in dot to flake sizes with sharp boundary,the intensity of T1 -weighted imaging decreased,T2 -weighted imaging and fluid attenuated inversion recovery increased.Eighty -two point one percent (64 /78 cases)of the patients were found to have the periventricular and subcortical WM involvement.The most frequently affected periventricular region was the posterior horn (91 .9%,68 /74 cases),followed by the anterior horn and temporal horn,and the least with the body involvement. The former three had a combined lesion tendency (55.4% -68.9%).There was an extensive involvement in the sub-cortical WMof parietal,frontal,temporal and occipital lobes respectively(73.5% -88.2%).Subcortical WM involve-ment of multiple lobes was common (accounted for 67.6% -77.9%).The enlargement of bilateral ventricles existed in 37.2%(29 /78 cases)of the patients and cystic changes in the subcortical WM of anterior temporal lobe could be found in 9.0% (7 /78 cases)patients.Calcification in 2 CT cases was reported.Corpus callosum and basal ganglia of all cases were normal.For cases with MRI scans more than once,WMlesions of 96.0%(24 /25 cases)patients became silent or self -restored.Conclusions The clinical presentations of CSNHL combined with WM lesions are mild,not paralleled with their multiple foci.It is considered as demyelination or a delay of myelination.Due to its benign course, it is probably not the contraindication for the cochlear implantation.

Objective To analyze the clinical characteristics of 3 unrelated boys with paroxysmal nonkinesigenic dyskinesia and developmental delay caused by de novo mutation in KCNMA1,and to expand the knowledge of clinical phenotype of KCNMA1 mutation.Methods Clinical data of patients were collected,including gender,age,condition of the perinatal period,personal history,and family history.And the features of genotype data were collected including features of attack,developmental milestones,physical examinations,treatments,and responses to treatment.The data including blood biochemical results,results of metabolic screening and genetic testing and the pedigree validation were collected,while the relationship between phenotype and genotype was analyzed.Results (1)Phenotypic features:3 unrelated boys were diagnosed.The ages of disease onset were 20 days,7 months and 13 months,respectively.All the patients manifested paroxysmal nonkinesigenic dyskinesia and were characterized by the episodes that occurred during wakefulness,presented with sudden onset of asymmetric limb dystonic posture,sometimes with nystagmus and strabismus,or sudden decrease of voluntary movement of limbs with hypotonia and occasional esotropia and yawning.There was no loss of awareness during attack.No precipitating factors were observed before attacks.The developmental milestones were delayed.Three children had no response to anti-epilepsy drug before diagnosis.After diagnosis,2 cases used Clonazepam and 1 case showed less attack.There was not any epileptic seizure until the last follow-up at the ages of 3 years and 6 months old,7 years old,and 5 years and 8 months old,respectively.The frequency of attacks was decreased.The episodes were recorded during video-electroencephalogram(EEG) monitoring,which showed normal ictal and interictal EEG.(2)Genotypic features:all 3 children were detected to have KCNMA1 genetic heterozygous missense mutation,while c.2650G>A (p.Glu884Lys) mutation was identified in 1 patient,and c.3158A>G(p.Asn1053Ser)mutation in the other 2 patients,but no such mutation was found in their parents.Conclusion This finding expands the phenotype of KCNMA1mutation.KCNMA1 should be considered as one of the candidate genes for screening in patients with early onset of paroxysmal nonkinesigenic dyskinesia without triggers,or early-onset of developmental delay,with or without epilepsy.

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 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 abnormalities in brain magnetic resonance imaging (MRI) and clinical manifestations of children with infantile spasms (IS) in the course of Vigabatrin (VGB) treatment.Methods:The imaging features of children with IS who took VGB orally and presented with brain MRI changes in Peking University First Hospital between September 2016 and June 2018 were analyzed retrospectively.Their use of VGB and the imaging findings were followed up.Meanwhile, the imaging and clinical features of 83 cases described in literature were summarized.Results:(1) Ten children diagnosed as IS were included.The average duration of VGB treatment at the time of imaging changes was 4.1 months, the average age was 11.8 months, and the average maximum dose was 90.6 mg/(kg·d). Brain MRI showed hyperintensities in bilateral thalamus, brainstem, basal ganglia and dentate nucleus diffusion-weight imaging (DWI), with or without T2WI, and T2 fluid attenuated inversion recovery(FLAIR) or slight hyperintensities.Brain MRI repeated in 5 patients 7-12 months later revealed that the original abnormal signals completely disappeared.Among them, 4 patients stopped using VGB and 1 patient continued to take VGB.(2) Literature review: 83 cases with IS treated with VGB from 16 literatures were reviewed, and the incidence of abnormal brain MRI was 22%-32%.The average age at initial VGB treatment was 8.0 months, and the average dose of VGB was 157.1 mg/(kg·d) when the brain MRI abnormalities were found.The MRI imaging showed high DWI signals in bilateral symmetrical thalamus, brainstem, basal ganglia (mainly pallidum) and dentate nucleus.During the follow-up of the 41 cases, no imaging abnormality was observed in 36 cases, improvement in 4 cases, and no significant change in 1 case.When MRI abnormalities were identified, 12.0%(10/83 cases) of the patients presented new clinical symptoms mainly in the extrapyramidal system, and the clinical symptoms of all children disappeared during the follow-up.Conclusions:During the course of VGB treatment of infantile spasms, brain MRI may suggest hyperintensities of DWI in the thalamus, brainstem, basal ganglia and dentate nucleus, but most are reversible.

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 analyze the clinical and imaging features of hypomyelination with brain stem and spinal cord involvement and leg spasticity (HBSL) due to mutations in DARS,and to identify DARS mutations responsible for HBSL.Methods Data on 2 HBSL patients who were admitted to the pediatric department of Peking University First Hospital from January 2009 through December 2016 were reviewed and the 2 patients were followed up.Targeted next generation sequencing,whole exome sequencing and Sanger sequencing were employed to identify potential genetic variations of the children and their parents.The clinical manifestations,MRI features and genotypic characteristics of two patients were reviewed,and the literature was reviewed.HBSL reported cases were searched with"leukoencephalopathies,DARS" on databases of PubMed,Wanfang,China National Knowledge Infrastructure and VIP from 1975 to 2017.The clinical manifestations and molecular features were analyzed.Results Both patients showed delayed motor development,but had normal cognitive development.At the age of 8 years,case 1 reached the most significant motor development milestone of only standing with help during the last follow-up.At the age of 9,case 2 could walk independently during the last follow-up.On physical examination,both showed leg spastcity,active tendon reflex,positive Babinski sign.Both patients had brain MRI findings of high T2WI signal in bilateral deep cerebral white matter,slightly lower T1WI,and no abnormal DWI signal.Lesions of case 1 were relatively extensive and involved subcortical white matter,corpus callosum and internal capsule.Spinal MRI scans for both patients showed no abnormal signals.Novel mutations in DARS gene-namely,c.1498_1499insTCA (p.500_501insIle) and c.1210A＞G (p.Met404Val),c.1432A＞G (p.Met478Val) and c.1210A＞G (p.Met404Val)were identified in case 1 and case 2 respectively.On the database,2 reports involving 13 foreign patients were retrieved.The age of disease onset was from 4 months to 18 years,and their initial symptoms were development delay or regression.Most of them presented with progressive lower extremity spasm,and the brain magnetic resonance imaging was characterized by hypomyelination in white matter.Clinical phenotypes of different age groups were significantly different.Conclusion We have reported two patients with HBSL in China,and 3 novel mutations in DARS,which is helpful for the diagnosis and genetic counseling of HBSL.

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.