微阵列比较基因组杂交技术对不明原因智力低下/生长发育迟缓患儿的分子诊断

目的　分析不明原因智力低下(ID)和(或)生长发育迟缓(DD)患儿潜在的致病性基因组不平衡, 及其与表型的相关性, 探讨高密度微阵列比较基因组杂交技术(array-CGH)在临床分子遗传学诊断中的应用价值。方法　采用array-CGH技术对16例ID/DD患儿进行全基因组扫描分析, 并用多重连接探针扩增技术(MLPA)对检出的基因组不平衡异位进行验证。结果　16例患儿高分辨G显带核型分析均无异常。6例(38%)患儿存在基因拷贝数异常(CNVs), 其中3例CNVs为正常多态性改变; 1例CNVs涉及4p16.3区域微缺失, 考虑为Wolf-Hirschhorn综合征; 1例CNVs涉及7q11.23区域微缺失, 考虑为Williams-Beuren 综合征; 另1例CNVs临床意义不明确, 包含2个重复突变, 该突变与智力低下、脑发育迟缓、特殊面容、隐睾、牙列不齐等有关, 证实该CNVs具有临床意义。结论 通过array-CGH技术对不明原因ID/DD患儿进行全基因组扫描, 可为部分患儿明确病因诊断。该技术作为一种高通量、快速的疾病研究手段, 在ID/DD的病因诊断中具有重要的临床意义。     

自行设计的多重链接探针扩增组合对多发畸形患儿的诊断价值

目的 尝试基于多重链接探针扩增（MLPA）技术设计的探针组合对多发畸形(MCA)患儿的诊断价值。方法 以临床发现≥2个的畸形表型患儿为病例,基于MLPA技术选择13种常见的MCA的关键基因和关键区域自行设计MLPA探针组合（SIGMA公司合成）,以微阵列比较基因组杂交（aCGH）作为金标准,检验该探针组合的诊断准确性,再以MLPA探针组合行MCA临床诊断效果评估,对MLPA探针组合阳性的病例结合临床资料进行分析。结果 ①MLPA探针组合涉及的13种常见MCA,包括：21-三体综合征（KCNJ6、DYRK1A、RCAN1基因）、18-三体综合征（MC2R、DTNA、TCF4基因）、13-三体综合征（EDNRB、CENPJ、ERCC5、FREM2基因）、1p36区域缺失综合征（GABRD、SKI、TP73基因）、 5q35.3区域缺失综合征（Sotos综合征,NSD1基因）、CHARGE综合征（CHD7基因）、7q11.23区域缺失综合征（Williams Beuren综合征,CLIP2、ELN、LIMK1基因）;22q11.21区域缺失、重复综合征（DiGeorge综合征,SNAP29、TBX1、ZNF74基因）、17p11区域缺失综合征（Smith-Magenis综合征,RAI1、MFAP4基因）、5p15.2区域缺失综合征（Cri du Chat综合征, CTNND2、TERT基因）、15q11-13区域缺失综合征（Prader-Willi综合征,OCA2、UBE3A、GABRB3基因）、4p16.3区域缺失综合征（Wolf Hirschhorn综合征,MSX1、WHSC1、LETM1基因）、17q21.31区域缺失综合征（MAP3K14、MAPT基因）。②35例MCA中,aCGH检测阳性11例（31.4%）,共诊断9种;MLPA探针组合检测阳性6例（17.1%）,共诊断4种;MLPA组合探针检测阳性的6例微缺失和重复与11例aCGH检测阳性一致,6例MLPA探针组合检测阳性的变异位点均位于设计的MLPA探针组合中,122例临床MCA中,MLPA探针组合检测阳性21例（17.2%）,诊断6种。③在157例MCA患儿中,应用MLPA探针组合共诊断阳性病例27例,共检出7种（53.8%）,分别为21-三体综合征8例,18-三体综合征1例,5p15区域缺失综合征3例,22q11区域重复综合征1例、缺失综合征9例,5q35区域缺失综合征1例,15q11-q13区域缺失综合征3例,7q11.23区域微缺失综合征1例。结论 自行设计合成的MLPA探针组合对非典型临床表型的MCA病例有较好的诊断价值。     

15q11.2-13.2微重复四倍体综合征1例并文献复习

目的 采用分子遗传学技术分析1例常规染色体核型拟诊为21/22三体的发育迟缓伴孤独症患儿,明确遗传学诊断。方法 收集患儿及其父母的外周血标本,常规提取基因组DNA,应用高分辨染色体核型分析（400-550带）检测患儿及其父母的染色体数目及结构,微阵列比较基因组杂交技术(array-CGH)筛查患儿的全基因组拷贝数变异,以荧光原位杂交技术（FISH）对异常的基因拷贝进行染色体精确定位和定量。结果 女,2岁,发育迟缓伴孤独症样表现。外侧眼角下垂、内眦赘皮。常规染色体核型检查（320带）分别为47,XX,+22和47,XX,+21。高分辨染色体核型分析显示,该患儿携带额外标记染色体（SMC）,核型为47,XX,+mar dn,尚不能确定是否为21/22三体携带者,患儿父亲高分辨率核型染色体分析提示为46,XY,母亲为46,XX,提示患儿携带SMC为新生突变。array-CGH检测显示15q11.2-13.2区域微重复（chr15:22684529-30730543,8.0 Mb,hg19）。FISH验证该SMC来源于15号染色体,由15q11.2-13.2区域二倍体及双着丝粒组成。患儿最终诊断为15q11.2-13.2微重复四倍体综合征。复习文献报道的15q11.2-13.2拷贝数增加病例的临床表型,微重复四倍体综合征的主要表型有智力低下/发育迟缓（100％）、肌张力低下（92.9％）、孤独症/孤独症样表现（71.4％）和癫痫（61.5％）等。结论 15q11.2-13.2微重复四倍体综合征是患儿发生精神发育迟滞伴孤独症的遗传学基础,array-CGH能够快速、准确地检测基因组的微小失衡。     

一例15号额外标记染色体致智力障碍、难治性癫癎伴中枢性性早熟患者的临床及遗传学分析

15号额外标记染色体是一种罕见的染色体异常,本文报道1例15号额外标记染色体患儿,就其临床诊治经过及遗传缺陷进行研究。患儿,女,9岁半,自幼智力、运动发育落后,7岁出现乳房发育,8岁半出现癫癎发作：发作形式多样,多种抗癫癎药物控制欠佳,头颅磁共振未见异常,脑电图提示癎样放电频繁。采用G显带核型分析、荧光原位杂交（FISH）、甲基化多重连接依赖性探针扩增技术（甲基化MLPA）和微阵列比较基因组杂交（array-CGH）等多种遗传学检测手段,明确患儿存在新生的15q重复：15q11-13区域母源性拷贝数复制增加,基因组重排的形式为47,XX,+inv dup （15）（pter→q13：q13→pter）。15q11-13区域拷贝数复制增加与智力障碍、难治性癫癎伴中枢性性早熟临床表现密切相关。建议对于不明原因智力障碍伴癫癎患儿进行高分辨染色体核型分析。     

中国Phelan-McDermid综合征1例患儿的临床及分子遗传学分析

目的 对1例不明原因的生长过快、发育迟缓患儿进行临床特征及基因诊断分析.方法 描述患儿临床特点;实验室检查采用常规G显带分析染色体核型,进一步通过多重连接依赖探针扩增(MLPA)对微小缺失片段进行拷贝数变异(CNVs)检测,同时应用比较基因组杂交芯片技术(array CGH)检测全染色体微小改变,并采用荧光原位杂交技术(FISH)对新发现的缺失片段进行实验验证.结果 1.患儿,男,1.5岁,宽额,尖下巴,生长过快,全面的发育迟缓,语言发育障碍、孤独症样表现.2.常规G带染色体核型示46,XY,MLPA结果显示患儿22q13段的SHANK3基因的9～23外显子及ACR、RABL2B基因的杂合性缺失,比较基因组杂交芯片分析证实22q13段杂合性缺失,并排除其他染色体的微改变,FISH进一步证实22q13段的缺失.结论 根据临床表现,结合各项实验室检查结果可诊断患儿为Phelan-McDermid综合征;针对性的CNVs适宜采用MLPA技术,而array CGH更宜作为全染色体CNVs的筛查.     

分子遗传学技术诊断MECP2重复综合征四例分析北大核心CSCD

目的 用多重连接探针扩增技术（MLPA）和微阵列比较基因组杂交技术（array-CGH）研究4例以运动、智力发育落后为主要表现的患儿甲基化CpG结合蛋白2基因（MECP2）基因突变特点.方法 取北京大学第一医院2012年6月至2014年4月收治的4例患儿及其中例2、例4母亲的外周血,提取基因组DNA;先对患儿用MLPA方法进行微缺失和微重复检测,然后用array-CGH进行分析进一步确定重复片段的大小;同时对2例患儿的母亲进行array-CGH和X染色体失活分析（XCI）.结果 4例患儿均表现为严重肌张力低下,运动、智力发育落后和语言发育障碍,除例2之外,另3例患儿婴儿期均反复发生肺炎.MLPA显示4例患儿均存在染色体Xq28重复;array-CGH检测显示4例患儿Xq28区域存在重复,4例患儿重复片段大小分别为14.931 Mb、0.393 Mb、0.482 Mb、0.299 Mb,经与UCSC（http：//genome.ucsc.edu/）数据库比对,4例患儿的重复片段均包含MECP2和宿主细胞因子C1基因（HCFC1）.例2和例4患儿的母亲存在Xq28重复,其中例4患儿母亲的重复片段起止位点和大小与患儿完全相同,例2母亲重复片段为0.343 Mb,小于患儿,近着丝粒断点与患儿不同,远端断点与患儿相同.X染色体失活分析发现母亲二条X染色体活性比例为0∶100,存在重复的一条X染色体完全失活,并且将发生重复的这条X染色体遗传给了患儿.结论 对于运动智力发育落后、肌张力低下、语言发育障碍和反复发生感染的患儿进行MLPA和array-CGH联合检测是诊断MECP2重复综合征的有效且特异的方法.     

22q11.2微缺失综合征的分子诊断及缺失范围检测

目的 分别采用多重连接探针扩增技术(MLPA)与荧光原位杂交技术(FISH)对22q1 1.2微缺失综合征外周血标本患者基因缺失/重复突变的类型及变异范围进行检测,分析在22q11.2微缺失综合征诊断中二者联合应用的诊断价值.方法 采集1例仅心脏异常患儿及其父母外周血,取200 μL外周血提取DNA后采用MLPA技术对患儿及其父母的染色体22q11.2缺失的范围进行检测,取外周血1 mL进行培养,采用DiGeorge/VCFS N25(D22S75)的FISH探针对培养后的中期淋巴细胞进行杂交.结果 患儿淋巴细胞分裂中期细胞应用FISH技术检测结果为22号染色体上的DiGeorge/VCFS N25(D22S75)区杂合性缺失;MLPA验证结果显示患儿与22q11.2微缺失综合征相关的6个探针对应的片段大小位置在3100的电泳图上荧光峰值相比健康对照明显出现减半,其父母亲均在正常范围.患儿的临床表现仅有先天性心脏病,无其他异常,与其基因缺失片段长度(2.0 Mb)极不相称.结论 联合应用FISH和MLPA检测22q11.2微缺失综合征,可以明显提高诊断的准确性.22q11.2微缺失综合征的临床表现与基因缺失片段的长度无相关性.     

5q14.3微缺失综合征导致婴儿痉挛症一家系的临床及遗传学研究

目的 分析婴儿痉挛症患儿的临床特征,并对患儿及其父母进行遗传学检测.方法 分析2014年3月接诊的1例婴儿痉挛症患儿面部特征、体格和智力发育状况.实验室检查采用常规G显带分析患儿及父母外周血染色体核型,单核苷酸多态性(SNP)基因芯片技术检测染色体微小改变,荧光原位杂交技术(FISH)验证结果,并对其父母染色体中期分裂象进行FISH检测.结果 患儿女,7岁,语言、运动、语言发育严重迟滞,生后4个月出现癫痫发作,临床诊断为“婴儿痉挛症”.体检见消瘦,面容特殊,存在刻板样不自主动作.头颅CT平扫提示“硬膜下积液”.脑电图检查提示:痫样放电频繁;高度失律.患儿及其父母常规染色体核型分析(400条带)均显示为正常核型.SNP微阵列技术检测显示该患儿染色体5q14.3区段微缺失,缺失片段为2.03 Mb,分子核型为arr5q14.3(87 538 430 ～ 89 565 757)× 1,该区段包含MEF2C基因.选择区域特异性RP11-293 L20探针,应用FISH技术对芯片结果进行验证,确认患儿5q14.3区域存在杂合缺失.父母染色体核型正常,无5q14.3区域缺失,无插入突变.结论 患儿染色体5q14.3区段发生缺失为婴儿痉挛症的病因.患儿为新发生的5q14.3微缺失综合征,父母再次生育时,建议选择SNP芯片技术进行产前诊断.     

2q31.1 微缺失综合征1 例报告并文献复习

目的提高对2q31.1微缺失综合征基因型及表型的认识。方法总结分析1例2q31.1微缺失综合征患儿的临床资料并复习相关文献。结果女性患儿,11月龄,自幼全面发育落后伴惊厥2次,特殊面容,肢端畸形,四肢肌张力减低,指、趾畸形;头颅MRI示胼胝体发育不良。应用染色体芯片检测技术,采用比较基因组杂交技术(array-CGH)证实2q31.1-2q31.3区域存在7.279 Mb微缺失:arr 2q31.1q31.3(174570453-181849708)×1。患儿确诊为2q31.1微缺失综合征。文献报道2q31.1微缺失综合征中HOXD基因簇及其调控序列的单倍体剂量不足导致肢端畸形;LNPK功能缺失性变异导致惊厥发作合并胼胝体发育不良的神经发育性疾病,表现为精神运动发育迟滞、智力障碍、肌张力减低、惊厥发作和胼胝体发育不全。该患儿神经系统受累表现与LNPK单基因变异的表型相似,推测患儿神经系统受累可能由LNPK单倍体剂量不足导致。结论对全面发育落后合并肢端畸形者需警惕2q31.1微缺失综合征。     

Phelan-McDermid综合征临床及微阵列比较基因组杂交芯片技术分析

目的探讨Phelan-McDermid综合征的临床表现及微阵列比较基因组杂交芯片技术(array CGH,aCGH)结果。方法回顾性分析1例Phelan-McDermid综合征患儿的临床资料;采用常规G显带分析染色体核型,运用aCGH检测全染色体微小改变。结果患儿染色体核型示正常女性核型,未发现染色体数目及结构异常;aCGH分析发现Chr22q13.2-qter缺失,并排除其他染色体微改变;确诊为Phelan-McDermid综合征。结论通过典型的临床表现和染色体微改变相关实验室检查可确诊Phelan-McDermid综合征;aCGH技术对于筛查该病并排除其他染色体微改变最有意义。     

Clinical aspects and genetics of Williams-Beuren syndrome. Clinical and molecular genetic study of 44 patients with suspected Williams-Beuren syndrome

BACKGROUND: The suspected diagnosis of Williams-Beuren syndrome (WBS), which is a retardation syndrome with great clinical variability, was cause for comparison of molecular genetic, molecular cytogenetic analysis to clinical symptoms. The results of the genetical analysis of a microdeletion of the elastin gene region on chromosome 7 were compared to the clinical symptoms. Are there any differences between symptoms in case of deletion or non-deletion? How informative are the molecular genetic, molecular cytogenetic analysis? PATIENTS AND METHODS: 44 patients with suspected diagnosis of WBS were examined using molecular genetic and molecular cytogenetic methods. The clinical symptoms as general symptoms, heart anomaly, dysmorphic signs and unusual neurobehavioural features were reported during clinical investigation in standardized questionnaires. The genomic DNA of the patients and their parents was analyzed using microsatellite markers. In some cases (e.g. uninformative microsatellite studies) we also used fluorescence in situ hybridization (FISH) with an elastin gene probe and performed a conventional chromosome banding analysis. RESULTS: 15 patients had a microdeletion. 4 patients had a deletion of the paternal allel and 7 patients showed the deletion of the maternal allel. The polymorphisms were of limited informativeness. In 2 cases microsatellite analysis was not able to determine whether the paternal or the maternal allel had been lost. In 2 cases the microsatellite analysis was uninformative so that FISH analysis was performed. All FISH analysis performed had an informative result. 80% of the children with a microdeletion of chromosome 7q11.23 showed the typical dysmorphic signs, 70% exhibited the typical WBS behaviour pattern, 50% had a specific heart anomaly. In contrast, in the group of children without a chromosomal microdeletion only 30-40% showed typical dysmorphic signs, only 10% had a typical heart anomaly and none of them showed specific behavioural changes. We found no indication to association of specific symptoms with paternal versus maternal origin of the deletion. The FISH analysis combined with a conventional chromosome banding analysis is very informative for diagnostic values. The results are compared to data of literature. CONCLUSIONS: Children with developmental retardation and WBS dysmorphic signs and an unusual behaviour should be examined by a molecular cytogenetic FISH analysis. If a microdeletion of band 7q11.23 is found a special cardiologic examination should be offered.     

葡萄糖转运子1缺陷综合征运动障碍特点和诊疗分析

目的 探讨葡萄糖转运子1缺陷综合征（GLUT1-DS）的临床特征和诊疗方法,分析运动障碍的诊断意义。方法 收集4例GLUT1-DS患儿的临床资料,分析其临床特点和治疗随访情况。结果 4例中男2例、女2例,起病年龄2~15个月。表现为运动障碍、癫癎发作和发育迟缓,均以癫癎发作为首诊原因。4例均有持续性共济失调、肌张力异常和构音障碍,2例有持续性震颤,发作性肢体瘫痪和眼球运动障碍各2例,劳累易诱发发作性症状。4例患儿的脑脊液葡萄糖及其与血糖的比值均降低。4例均检测到SLC2A1基因突变,均接受生酮饮食治疗,生酮比3：1~2：1,发作性症状5周内完全缓解。结论 对于合并多样化运动障碍的智力运动发育迟缓的癫癎患儿需考虑GLUT1-DS,生酮饮食的生酮比维持在3：1~2：1可起效。     

Children with autistic behavior in a self-contained unit in the public schools

The diagnosis of "autism" has been used to encompass a heterogeneous group of children who may differ in etiology, clinical manifestations, prognosis, and needed treatment. This paper presents the results of a comprehensive evaluation, using strict diagnostic criteria, of 33 children comprising the entire population of a self-contained unit for "autistic" children in the public school system of Hillsborough County, Florida. Only five of the children fit the criteria for early infantile autism. Six were diagnosed as suffering from schizophrenia, two as atypical developmental disorders. Twelve of the 33 showed evidence of neurological or recognized genetic abnormality, five had specific developmental language disorders, and three were severely retarded, cause unknown. Of the 12 children with evidence of neurological disease, five had chromosome abnormalities evident on cytogenetic study, two had high serum Cux++, one had histidinemia, one had maternal rubella, and three had dyskinesis of unknown origin. The heterogeneous nature of this group underlines the need for comprehensive evaluation of the autistic syndrome.     

4号染色体4q21/q22缺失综合征1例报告

目的提高对4q21/q22缺失综合征的临床和基因特征的认识。方法回顾性分析1例有特殊面容及体格智力发育迟缓患儿的临床资料及基因检测结果。结果患儿,女,2个月。表现为喂养困难,发育迟缓,新生儿期肌张力低下,头大,前额及枕部突出,小手足;合并先天性心脏病。应用染色体微阵列芯片分析技术发现患儿4q21.21q22.2区域有一缺失,缺失片段大小约15.26 Mb,至少包含76个基因,确诊为4q21/q22缺失综合征。结论患儿有典型面容特征,发育迟缓,伴其他系统累及时应考虑4q21/q22缺失综合征可能,染色体芯片检测技术有助于明确诊断。     

The genetics of autism

Autism is a complex, behaviorally defined, static disorder of the immature brain that is of great concern to the practicing pediatrician because of an astonishing 556% reported increase in pediatric prevalence between 1991 and 1997, to a prevalence higher than that of spina bifida, cancer, or Down syndrome. This jump is probably attributable to heightened awareness and changing diagnostic criteria rather than to new environmental influences. Autism is not a disease but a syndrome with multiple nongenetic and genetic causes. By autism (the autistic spectrum disorders [ASDs]), we mean the wide spectrum of developmental disorders characterized by impairments in 3 behavioral domains: 1) social interaction; 2) language, communication, and imaginative play; and 3) range of interests and activities. Autism corresponds in this article to pervasive developmental disorder (PDD) of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition and International Classification of Diseases, Tenth Revision. Except for Rett syndrome--attributable in most affected individuals to mutations of the methyl-CpG-binding protein 2 (MeCP2) gene--the other PDD subtypes (autistic disorder, Asperger disorder, disintegrative disorder, and PDD Not Otherwise Specified [PDD-NOS]) are not linked to any particular genetic or nongenetic cause. Review of 2 major textbooks on autism and of papers published between 1961 and 2003 yields convincing evidence for multiple interacting genetic factors as the main causative determinants of autism. Epidemiologic studies indicate that environmental factors such as toxic exposures, teratogens, perinatal insults, and prenatal infections such as rubella and cytomegalovirus account for few cases. These studies fail to confirm that immunizations with the measles-mumps-rubella vaccine are responsible for the surge in autism. Epilepsy, the medical condition most highly associated with autism, has equally complex genetic/nongenetic (but mostly unknown) causes. Autism is frequent in tuberous sclerosis complex and fragile X syndrome, but these 2 disorders account for but a small minority of cases. Currently, diagnosable medical conditions, cytogenetic abnormalities, and single-gene defects (eg, tuberous sclerosis complex, fragile X syndrome, and other rare diseases) together account for <10% of cases. There is convincing evidence that "idiopathic" autism is a heritable disorder. Epidemiologic studies report an ASD prevalence of approximately 3 to 6/1000, with a male to female ratio of 3:1. This skewed ratio remains unexplained: despite the contribution of a few well characterized X-linked disorders, male-to-male transmission in a number of families rules out X-linkage as the prevailing mode of inheritance. The recurrence rate in siblings of affected children is approximately 2% to 8%, much higher than the prevalence rate in the general population but much lower than in single-gene diseases. Twin studies reported 60% concordance for classic autism in monozygotic (MZ) twins versus 0 in dizygotic (DZ) twins, the higher MZ concordance attesting to genetic inheritance as the predominant causative agent. Reevaluation for a broader autistic phenotype that included communication and social disorders increased concordance remarkably from 60% to 92% in MZ twins and from 0% to 10% in DZ pairs. This suggests that interactions between multiple genes cause "idiopathic" autism but that epigenetic factors and exposure to environmental modifiers may contribute to variable expression of autism-related traits. The identity and number of genes involved remain unknown. The wide phenotypic variability of the ASDs likely reflects the interaction of multiple genes within an individual's genome and the existence of distinct genes and gene combinations among those affected. There are 3 main approaches to identifying genetic loci, chromosomal regions likely to contain relevant genes: 1) whole genome screens, searching for linkage of autism to shared genetic markers in populations of multiplex families (families with >1 affected family member; 2) cytogenetic studies that may guide molecular studies by pointing to relevant inherited or de novo chromosomal abnormalities in affected individuals and their families; and 3) evaluation of candidate genes known to affect brain development in these significantly linked regions or, alternatively, linkage of candidate genes selected a priori because of their presumptive contribution to the pathogenesis of autism. Data from whole-genome screens in multiplex families suggest interactions of at least 10 genes in the causation of autism. Thus far, a putative speech and language region at 7q31-q33 seems most strongly linked to autism, with linkages to multiple other loci under investigation. Cytogenetic abnormalities at the 15q11-q13 locus are fairly frequent in people with autism, and a "chromosome 15 phenotype" was described in individuals with chromosome 15 duplications. Among other candidate genes are the FOXP2, RAY1/ST7, IMMP2L, and RELN genes at 7q22-q33 and the GABA(A) receptor subunit and UBE3A genes on chromosome 15q11-q13. Variant alleles of the serotonin transporter gene (5-HTT) on 17q11-q12 are more frequent in individuals with autism than in nonautistic populations. In addition, animal models and linkage data from genome screens implicate the oxytocin receptor at 3p25-p26. Most pediatricians will have 1 or more children with this disorder in their practices. They must diagnose ASD expeditiously because early intervention increases its effectiveness. Children with dysmorphic features, congenital anomalies, mental retardation, or family members with developmental disorders are those most likely to benefit from extensive medical testing and genetic consultation. The yield of testing is much less in high-functioning children with a normal appearance and IQ and moderate social and language impairments. Genetic counseling justifies testing, but until autism genes are identified and their functions are understood, prenatal diagnosis will exist only for the rare cases ascribable to single-gene defects or overt chromosomal abnormalities. Parents who wish to have more children must be told of their increased statistical risk. It is crucial for pediatricians to try to involve families with multiple affected members in formal research projects, as family studies are key to unraveling the causes and pathogenesis of autism. Parents need to understand that they and their affected children are the only available sources for identifying and studying the elusive genes responsible for autism. Future clinically useful insights and potential medications depend on identifying these genes and elucidating the influences of their products on brain development and physiology.     

儿童保健门诊语音障碍儿童初诊现状分析

目的 了解儿童保健科医生对语音障碍（SSD）的认识。方法 收集并分析2017年1月至2019年5月期间初次就诊并诊断为SSD的506例儿童的临床资料。结果 506例SSD儿童中，90.5% SSD儿童病史中描述发育行为相关表现；97.6%完善发育行为评估，以筛查性智能及发育测试为主（485/506，95.8%）。116例（22.9%）共患神经发育障碍性疾病，最常见的为语言障碍、全面发育迟缓和智力障碍，45.7%（53/116）发育行为相关病史中未记录异常表现。家属自觉听力异常儿童的神经发育障碍性疾病发生率高于家属自觉听力正常儿童，体查时对声源反应异常儿童的神经发育障碍性疾病发生率高于对声源反应正常儿童（P < 0.05）。506例SSD儿童中，病史中及体查时未关注听力的比例分别达33.2%、31.2%。92例（18.2%）完善诊断性听力测试，听力损失检出率为12%（11/92）。11例听力损失儿童病史中，3例既往听力筛查通过，3例家属自觉听力正常，7例体查时对声源反应正常。结论 SSD儿童易共患神经发育障碍性疾病，关注交流表现有助于其诊断，但病史询问易遗漏，应结合发育行为评估。SSD儿童的神经心理发育状况得到了儿童保健医师的关注，发育行为评估完成率高，但目前以筛查性智能发育测试为主。SSD儿童听力损失检出率高，儿童保健医生对其听力损失问题认识不足，诊断性听力测试未得到重视，临床不应以既往听力筛查结果或生活场景中儿童对声源的反应评估听力水平。     

Elastin Mutation Screening in a Group of Patients Affected by Vascular Abnormalities

Supravalvular aortic stenosis is an uncommon but well-characterized congenital form of left ventricular outflow obstruction. The lesion involves the ascending aorta and often occurs in association with pulmonary arterial stenoses or stenoses of other arteries, especially at major branch points. It can occur sporadically, as an autosomal dominant condition, or as one component of Williams-Beuren syndrome. In fact, the clinical and structural characteristics of supravalvular aortic stenosis are identical in both syndromic and nonsyndromic cases. The severity of supravalvular aortic stenosis varies; but if it is left untreated, it may result in heart failure, myocardial infarction, and sudden death. Supravalvular aortic stenosis in Williams-Beuren patients occurs as a consequence of a complete deletion of one copy of the elastin gene on chromosome 7q11.23. However, the underlying genetic cause of isolated supravalvular aortic stenosis has been identified as translations, gross intragenic deletions, and point mutations that disrupt the elastin gene. We report the results obtained in a mutation screening of the elastin gene in 28 patients with supravalvular aortic stenosis and other vascular abnormalities. The aim of the screening was to characterize the molecular cause of this lesion. We have detected 11 changes, including nine polymorphisms and two novel putative missense mutations. Grant support: 98TV1110 from “Fundació Marató TVS”, and V2003RedC-07 from “Institute de salud Carlos III”.     

Applications and limits of prenatal diagnosis (author's transl)

By means of antenatal diagnosis mainly chromosome aberrations, malformations and inborn errors of metabolism may be recorded. At present there exist four ways for gaining information on the fetus in a pregnant woman: analysis of the amniotic fluid after amniocentesis, fetoscopy, ultrasound diagnosis and analysis of the maternal serum. Prenatal diagnosis becomes necessary in pregnancies where a child suffering from a severe illness or malformation is to be expected. Only if the disorder can be diagnosed by antenatal diagnosis and its severity justifies abortion prenatal diagnosis is to be carried out. Most cases transferred to antenatal diagnosis are pregnancies of women in advanced age because of the increasing risk of carrying a child with Down's syndrome. Another important group is formed by pregnant women with a previous child with Down's syndrome or another chromosomal disorder.