先天性中枢性低通气综合征1例并文献复习

目的 提高对先天性中枢性低通气综合征(CCHS)的临床和基因特征的认识。方法 总结分析1例CCHS患儿的临床表现、诊断和基因检测结果,并进行文献复习。结果 男,7月龄。以肺部感染、撤机困难入院。入院肺部感染基本控制撤机后,患儿睡眠状态下出现呼吸浅慢,再次予机械通气,模式为双水平正压通气。患儿觉醒时呼吸活跃,入睡后依赖呼吸机,自主呼吸减慢,潮气量减小,出现CO2储留。同时相关辅助检查排除了原发心、肺、脑、神经肌肉及代谢性疾病,临床诊断为CCHS。取患儿及其父母静脉血行PHOX2B基因序列检测,显示患儿PHOX2B第3外显子存在突变（基因型为20/25）,其父母未检出突变,确诊为CCHS。患儿随访至11月龄,呼吸和循环情况尚平稳。结论 CCHS以觉醒时有充足通气,睡眠状态下通气不足为主要表现,行PHOX2B基因突变分析可确诊CCHS。     

多发性线粒体功能障碍综合征6 型1 例报告并文献复习

目的探讨PMPCB基因变异导致多发性线粒体功能障碍综合征6型(MMDS6)的临床表型和基因变异特点。方法回顾分析1例MMDS6患儿的临床资料,并结合文献进行复习。结果患儿,男,5月龄。表现为体质量不增、喂养困难、运动发育倒退、四肢肌张力低,伴高乳酸血症、心力衰竭。心脏彩超示肺动脉高压。全外显子和线粒体基因测序显示PMPCB基因c.524GA纯合核苷酸变异,父母均为杂合子,该纯合变异尚未见文献报道。结论 PMPCB基因c.524GA纯合核苷酸变异是MMDS6的致病变异。二代基因测序有助于基因型诊断。     

先天性中枢性低通气综合征四例临床研究

目的 研究先天性中枢性低通气综合征（congenital central hypoventilation syndrome,CCHS）的临床特征,提高对CCHS的认识,以便早期诊断和治疗,提高临床诊疗水平.方法 分析2012年4月至2013年6月收治的反复青紫、高碳酸血症、撤机失败的4例患儿临床资料,经过相关检查,除外可导致低通气的心、肺、神经肌肉功能障碍原发病,并行CCHS主要致病遗传基因Phox2b检测,结合文献,对照CCHS诊断标准.结果 4例患儿均有CCHS典型临床特征：清醒时有足够的通气,睡眠时呼吸频率减慢,通气不足,出现青紫、高碳酸血症,对低通气所致的高碳酸血症和低氧血症无觉醒反应.基因检测均证实存在Phox2b基因突变,2例经予以无创通气治疗,l例3个月大时顺利出院,继续家庭无创通气,1例1个月时出院,家庭监护治疗,随访至今,均生长发育良好.结论 对于持续存在的睡眠状态下通气不足、反复高碳酸血症、撤机失败,而无心、肺、神经肌肉功能障碍原发病,需考虑CCHS,Phox2b基因检测可作为CCHS的重要诊断手段,无创通气治疗可为CCHS患儿提供有效的呼吸支持.     

先天性中枢性低通气综合征6例病例系列报告

正1病例资料回顾性收集2017年3月至2021年2月在浙江大学医学院附属儿童医院(我院)住院确诊的6例先天性中枢性低通气综合征(CCHS)病例。CCHS诊断符合以下标准[1,2]:(1)存在肺泡低通气(低氧血症及高碳酸血症),并排除心肺及神经肌肉原发疾病;(2)基因检测证实存在PHOX2B基因突变。     

3 M 综合征 1 例报告并文献复习

目的探讨3M综合征的临床特征及致病基因。方法回顾分析1例3M综合征患儿的临床资料,并抽提患儿及父母外周血DNA,通过Agilent Sure Select外显子捕获和Illumina Hi Seq测序平台进行测序分析,同时对发现的突变基因进行Sanger测序法验证。结果女性患儿,6月龄,特殊面容,生长落后。患儿的CUL7基因(NM_014780.4)存在错义变异c.4898CT,p.T1633M,父母均为杂合突变。确诊为3M综合征。结论患儿为3M综合征主要致病基因CUL7突变。对于临床表型疑似病例应早期进行基因检测以明确诊断。     

COL2A1 基因变异相关腭裂1 例报告并文献复习

目的探讨腭裂患儿的临床特征及致病基因。方法回顾分析1例COL2A1基因变异腭裂患儿的临床资料,并复习c.2292 delA变异相关腭裂相关文献。结果患儿男,生后即发现上腭畸形,临床表现有双眼略凸出、哭声低哑、喉中痰鸣、呼吸阵发性急促有吐沫、下颌小、舌短、软腭及悬雍垂裂、硬腭部分裂开。全外显子组基因靶向捕获-高通量测序示患儿COL2A1基因存在c.2292 delA移码缺失变异。文献复习发现,COL2A1基因移码变异已在人类基因变异数据库(HGMD)和ClinVar中报道,但本例患儿的变异位点未有报道,在正常人群数据库gnomAD、千人数据库和ExAC数据库中也均未被收录,为罕见变异。结论COL2A1基因变异c.2292 delA相关腭裂较罕见,基因检测可协助诊断。     

5例糖原贮积症Ⅸc型患儿临床和PHKG2基因突变分析

目的分析5例糖原贮积症(GSD)Ⅸc型患儿的临床、生化及基因突变特点。方法回顾分析5例GSD Ⅸc型患儿的临床情况,并采用靶向测序技术进行基因分析,Sanger测序验证所发现的PHKG2基因突变及其父母来源。结果5例患儿均表现为明显肝大和矮小,4例有运动耐力差;均有空腹低血糖,肝酶中重度升高,血三酰甘油升高;肝脏超声示无肝硬化。靶向测序发现5例患儿均携带PHKG2基因纯合或复合杂合致病或可能致病突变,发现1种已报道突变p.E157K和5种新突变(p.E56X,p.R185X,c.79_88delins TCTGGTCG,c.761del C,p.R279C),p.E157K为患儿的热点突变(50%)。结论靶向测序有助于确诊GSD Ⅸc型,p.E157K为热点突变。     

先天性全身脂肪营养不良一家系临床及基因变异分析

目的探讨先天性全身脂肪营养不良症(CGL)的临床特征及基因变异特点。方法回顾分析1对BSCL2基因变异致CGL双胎患儿的临床资料及其家系基因检测结果。结果患儿均为男性,4月龄,均表现为全身脂肪组织消失,肝脾肿大,全身少量色素沉着。实验室检查示高三酰甘油血症。提取双胎中哥哥及父母的外周血,进行全外显子组基因测序并经Sanger测序验证,结果显示患儿存在BSCL2基因c.974 dup(p.Ile 326 HisfsTer 12)纯合变异,为致病变异,确诊为CGL2。其父母均携带c.974dup杂合变异。检测其家系10人(三代)的BSCL2基因显示,双胞胎弟弟亦为BSCL2基因c.974dup纯合变异,诊断为CGL2;其祖母、外祖父、大伯、小舅以及同胞哥哥为该位点的携带者,符合常染色体隐性的遗传规律。结论发现2例同卵双胎CGL2,国内尚未见报道。     

SRCAP 基因变异致扩张型心肌病1 例家系分析并文献复习

目的分析SRCAP基因变异致扩张型心肌病(DCM)家系基因型与临床表型的相关性。方法回顾分析1例特发性DCM患儿的临床资料,利用全外显子测序技术检测致病基因,以Sanger测序验证,利用I-TASSER软件预测致病基因对蛋白质结构及功能的影响。结果患儿男性,16月龄,临床特征为反复呼吸道感染、心肌酶高、心肌收缩力减低、高乳酸血症、语言发育落后,无恶性心律失常。全外显子测序发现SRCAP c.452-453del,pPhe151Cysfs*71基因变异,为新发杂合变异,常染色体显性遗传,以往未有报道。SRCAP基因第151位半胱氨酸在不同物种之间具有高度保守性。I-TASSER软件预测野生型蛋白质3230残基,变异体蛋白质220残基;亲疏水性分析野生型亲水性Sum(求和)(5:3226)=-1449.44,变异体亲水性 Sum(求和)(5:216)=-126.55。结论SRCAP基因c.452-453del(pPhe151Cysfs*71)变异可导致肽链合成提前终止、蛋白质结构截短及亲疏水性发生明显改变,结合患儿临床表型此变异可能是DCM新发现的致病变异。     

椎体软骨发育不良伴免疫调节异常1 例基因诊断及文献复习

目的探讨1例罕见的矮小症伴多系统异常病例的临床和实验室诊断。方法采用全外显子组测序技术,结合高通量数据分析流程进行基因检测,并采用Sanger测序进行验证。结果患儿,男,14岁,发现身材矮小5年余。身高132cm,有面部色素沉着斑点和甲癣。外翻足已手术矫正,因自身免疫性溶血性贫血长期口服泼尼松治疗。头颅CT示两侧基底节、两侧额叶及左侧顶叶多发性钙化。脊柱平片示胸腰椎椎体变扁。全外显子组测序结合Sanger测序验证,发现ACP5基因纯合致病突变(c.643GA,p.G215R),确诊为罕见的椎体软骨发育不良伴免疫调节异常(SPENCDI)。结论全外显子组测序是确诊疑难罕见病的有效方法之一。     

Congenital central hypoventilation syndrome in children

Congenital central hypoventilation syndrome (CCHS) is a rare, lifelong condition wherein control of breathing is abnormal and patients present with symptoms of alveolar hypoventilation. The severity of hypoventilation varies and although most patients present in the neonatal period, late onset cases have been reported. In 2003, it was discovered that mutations in the PHOX2B gene were responsible for CCHS. This gene also plays a role in neural crest cell migration, and many patients present with symptoms of autonomic dysfunction in addition to hypoventilation. The pathophysiology responsible for hypoventilation remains unclear although a unifying hypothesis is that the abnormality is located in areas of the brain involved in integration of chemoreceptor afferent pathways for ventilation. The goal of treatment for CCHS is to ensure adequate ventilation during wakefulness and sleep. A variety of ventilation modalities are available including positive pressure ventilation via tracheostomy, non-invasive ventilation via nasal mask, and diaphragmatic pacing. With close monitoring and support, children with CCHS can be expected to function well in society and have a good quality of life.     

Congenital central hypoventilation syndrome: not just another rare disorder

Congenital central hypoventilation syndrome (CCHS) is a rare syndrome, present from birth, and is defined as the failure of automatic control of breathing. Patients have absent or negligible ventilatory sensitivity to hypercapnia and hypoxaemia during sleep and wakefulness. Therefore, especially while asleep, children with CCHS experience progressive hypercapnia and hypoxaemia. They lack arousal responses and sensations of dyspnoea to the endogenous challenges of isolated hypercapnia and hypoxaemia and to the combined stimulus of hypercapnia and hypoxaemia. Patients with CCHS do not exhibit signs of respiratory distress when challenged with hypercarbia or hypoxia. The diagnosis is one of exclusion, ruling out any primary pulmonary, cardiac, metabolic or neurologic cause for central hypoventilation. CCHS is associated with other manifestations of autonomic nervous system dysfunction, including Hirschsprung's disease. All patients with CCHS require lifelong ventilatory support during sleep but some will be able to maintain adequate ventilation without assistance while awake once past infancy. However, some CCHS patients require ventilatory support for 24h/day. Modalities of home mechanical-assisted ventilation include positive pressure ventilation via tracheostomy, non-invasive positive pressure ventilation (bi-level ventilation), negative pressure ventilation and diaphragmatic pacers. Supplemental oxygen alone is inadequate treatment. With early diagnosis and adequate ventilatory support, these children can have good outcomes and lead productive lives.     

<Emphasis Type="Italic">PHOX2B</Emphasis> mutations in patients with Ondine–Hirschsprung disease and a review of the literature

Congenital central hypoventilation syndrome (CCHS), also known as Ondine's curse, is characterized by idiopathic failure of autonomic breathing and is often associated with neurocristopathies such as Hirschsprung disease (HSCR). CCHS is caused by mutations in the paired-like homeobox 2B (PHOX2B) gene, often manifest as polyalanine repeat expansions. Herein, we report the cases of two unrelated Korean patients with Ondine–Hirschsprung disease. The patient's clinical manifestations were apnea and cyanosis requiring immediate endotracheal intubation, recurrent hypoventilation with hypercapnia, hypoxia after ventilator removal, and abdominal distension since birth. Intestinal biopsies were performed and the absence of ganglion cells in the colon was consistent with HSCR. We performed direct sequencing analysis in the PHOX2B and RET genes and fluorescence polymerase chain reaction in order to determine the polyalanine tract expansion in exon 3 of the PHOX2B gene. Expansion mutations were detected in both patients; one had 20/24 repeats and the other had 20/27 repeats. The 20/24 genotype has not been previously described in severe CCHS phenotypes and associated HSCR. We believe that the information in this report will improve our understanding of the phenotypic and genotypic heterogeneities of CCHS and HSCR.     

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??Objective??To detect pathogenic genes of short stature with unknown etiology by a targeted next generation sequencing panel to analyze the correlation between genotypes and clinical phenotypes. Methods??A total of 77 children diagnosed with unexplained short stature were enrolled for the study. These children were treated in Ruijin Hospital of Shanghai Jiao Tong University from 2007 to 2015. To search for genetic variation in 187 candidate genes which were associated with growth?? we constructed a targeted next generation sequencing panel encompassing the coding regions of 187 genes. According to ACMG Guidelines??the sites of variation were determined. Sanger sequencing was used to verify the suspected pathogenic genes variation. The relationship between genotype and clinical phenotype was analyzed. Results??Including 5 pathogenic variants?? one likely pathogenic variant and one variant of uncertain significance?? we identified 7 heterozygous variants of 7 cases in 77 cases of short stature with unknown etiology. A pathogenic variant p.D2407fs of ACAN gene was found in a case with advanced bone age. There were 3 reported pathogenic variants?? including p.A72G?? p.I282V and p.P491S of PTPN11 gene?? which were diagnosed as Noonan syndrome. A case carrying known pathogenic variant COL2A1??p.R904C?? was diagnosed as Stickler syndrome. We still got one likely pathogenic variant COMP??p.D401N???? which could cause multiple epiphyseal dysplasia. There was a familial short stature of delayed bone age carrying a variant??p.S289Y?? of uncertain significance??in which the genotype was in accordance with the clinical phenotype. Conclusion??The ACAN gene defection is associated with the idiopathic short stature with advanced bone age. The likely pathogenic variant COMP??p.D401N?? may cause multiple epiphyseal dysplasia. The newly-found heterozygous varians??p.S289Y?? of GHSR gene may result in short stature??which needs further function verification.     

Congenital Central Hypoventilation Syndrome with PHOX2B Gene Mutation

A term baby developed hypoventilation on day 1 of life requiring mechanical ventilation and had subsequent difficulty in weaning. Diagnostic workup for pulmonary, cardiac, metabolic, sepsis and structural CNS diseases were negative. In view of persistent hypoventilation despite raised pCO₂ levels in absence of any sedation, the diagnosis of Idiopathic. Congenital Central Hypoventilation Syndrome (CCHS) was considered. The baby was tested for Paired-like Homeobox 2B (PHOX2B) gene mutation and was found to have expanded alleles containing 10 polyalanine repeats producing genotype of 20/30 on chromosome 4p12 (The normal being 20/20). This is the first report of a neonate from India with genetically confirmed CCHS.     

Later-onset congenital central hypoventilation syndrome due to a heterozygous 24-polyalanine repeat expansion mutation in the PHOX2B gene

Aim: to describe a family with later onset congenital central hypoventilation syndrome (LO-CCHS) and heterozygosity for a 24-polyalanine repeat expansion mutation in the PHOX2B gene, rendered phenotypically apparent with exposure to anesthetics.
Case summary: An otherwise healthy 2.75-year-old boy presented with alveolar hypoventilation after adenoidectomy and tonsillectomy for obstructive sleep apnea, requiring invasive ventilatory support during sleep. He had a heterozygous 24-polyalanine repeat expansion in the PHOX2B gene (20/24 genotype), a genotype that has not been previously described in association with CCHS or LO-CCHS symptoms. Clinical findings in members of the family with the same 20/24 genotype ranged from asymptomatic to prolonged sedation after benzodiazepines.
Conclusion: CCHS should be suspected in individuals presenting with unexplained hypoventilation and/or seizures after anesthetics or sedatives. This is the first report of LO-CCHS in a kindred with the PHOX2B 20/24 genotype. The incomplete penetrance observed in this family suggests a gene–environment interaction.     

基于目的基因捕获的二代测序技术对质谱检测阳性患儿的分子诊断

目的运用基于目的基因捕获的二代测序技术,对质谱检测阳性的遗传代谢病疑似患儿进行基因检测,探讨二代测序技术在遗传代谢性疾病诊断的应用价值。方法回顾性收集复旦大学附属儿科医院遗传代谢专科门诊收治的、质谱检测阳性遗传代谢病疑似患儿的剩余干血滴滤纸片,行目的基因捕获的二代测序,行Sanger进行验证。结果 2013年6月至2014年5月共有48例质谱检测阳性的遗传代谢病疑似患儿纳入本文分析,40例完成二代测序,男性22例。40例测序标本中,29例(72.5%)检测到与临床症状相符的基因变异,包括甲基丙二酸血症6例,citrin缺陷病6例,高苯丙氨酸血症5例,戊二酸血症3例,其他遗传代谢病9例。2例疑似citrin缺陷病的标本在SLC25A13基因上仅检测到单个致病性突变,进一步行长片段PCR,检测到2例标本均存在3 kb的杂合插入突变。结论基于目的基因捕获的二代测序技术在对临床疑似遗传代谢病的检测中,有着较高的阳性诊断率,不仅能为临床医生提供可靠的分子诊断依据,而且可以根据致病基因对疾病分型,有效地为后续的临床治疗和遗传咨询提供依据。     

儿童肺血管疾病的影像学诊断

肺血管疾病是一组累及包括各级肺动、 静脉及肺毛细血管在内的肺循环疾病， 其致病因素各异， 病理改变多样。儿童与成人肺血管疾病从致病因素、 发病机制、 病理生理学， 临床表现及预后等方面均存在较大差异。儿童肺血管性疾病包括以下几大类别： （1）先天性肺血管病变，包括各级别的肺动、 静脉畸形、 肺毛细血管发育异常、 气管支气管畸形伴肺血管畸形、 血管淋巴异常等； （2）肺血管栓塞性病变， 包括炎症性栓塞， 肿瘤性栓塞； （3）肺血管炎性病变； （4）肺动脉高压性病变； （5） 肺部血管源性肿瘤。儿童常见肺血管疾病常用的影像学检查方法有胸部X线平片、 超声心动图、 胸部CT增强扫描、 肺血管造影检查、 核医学肺通气/灌注显像等。该文对上述儿童常见肺血管疾病影像学检查方法的选择及影像学诊断要点进行概述。