12p三体新生儿1例临床及细胞分子遗传学分析

目的探讨12p三体新生儿的临床及细胞分子遗传学特点。方法回顾1例经外周血行淋巴细胞常规G显带染色体核型分析,高通量测序染色体组拷贝数分析(CNV)并经淋巴细胞间期荧光原位杂交(FISH)技术确认的12p三体新生儿的临床资料。结果患儿外周血染色体核型为47,XX,+mar,父母染色体核型均正常;CNV检出患儿12p13.33-p11.1(160 001～34 860 000)区域重复,片段大小为34.7 Mb;外周血淋巴细胞间期FISH显示患儿所有间期细胞核12号染色体短臂均存在3个信号,无嵌合体存在。确诊为12p三体。结论结合临床特征、外周血染色体核型分析、CNV及FISH技术可有效确诊12p三体。     

新发8p 重复伴缺失综合征患儿细胞分子遗传学研究

目的探讨8号染色体短臂倒位重复伴末端缺失[inv dup del(8p)]综合征的临床特征及细胞分子遗传学特点。方法回顾分析1例inv dup del(8p)综合征患儿的临床资料以及细胞分子遗传学分析资料。结果 6月龄女性患儿,具有发育迟缓、特殊面容、先天性心脏病及喉软化症等临床表现。外周血淋巴细胞染色体核型分析显示,患儿为46,XX,der(8)inv dup(8)(p21),del(8)(p23),父母均无异常;高通量测序染色体组拷贝数分析(CNV)精确定位拷贝数异常改变的染色体片段区域,检出患儿在8p23.3-p23.1(160 001-7 120 000)区域缺失6.96 Mb片段,在8p23.1-p21.1(12 560 001-27 940 000)区域,重复15.38 Mb片段;荧光定量PCR验证CNV显示在重复和缺失片段之间有一个5.4 Mb的拷贝数正常片段。结合临床表现及各检测结果确诊患儿为inv dup del(8p)综合征。结论结合临床特征、外周血染色体核型分析、CNV及荧光定量PCR技术可有效确诊inv dup del(8p)综合征。     

92例先天性智力低下患儿细胞遗传学分析

目的：探讨先天性智力低下患儿染色体核型变化。方法：取92例先天性智力低下患儿外周血混合淋巴细胞培养,制备染色体,利用G显带技术对其进行染色体核型分析。结果：92例患儿中,检出异常染色体核型43例,检出率47%。其中,常染色体异常35例,占38%;性染色体异常8例,占9%;新发现1例智力低下异常核型:45,XX,psu dic（11;9）（p15;p24）。结论：染色体异常是导致先天性智力低下的重要原因,外周血细胞遗传学分析有助于提高先天性智力低下病人的遗传学筛查率。     

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。     

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.     

SRY基因检测在儿童性发育疾病诊断中的应用

目的：应用SRY基因直接测序检测技术和外周血染色体核型分析技术对外生殖器模糊的幼儿及青春期儿童进行检查以明确诊断。方法：采用常规G显带方法分析20例外生殖器模糊的患儿染色体核型,用PCR技术扩增其SRY基因,进行基因测序,分析是否存在SRY基因及SRY基因是否存在突变情况。结果：20例患儿中SRY基因阳性的有17例,阴性3例。直接测序结果显示所有SRY基因阳性患者该基因均未发生突变。染色体核型分析中检出4例特殊核型为：46, XY, del (Y) (q12)/45, X、46, XY, add (Y) (p11)、46, XY, r (9)及46, XY, 9 qh+。结论：SRY基因检测有助于明确儿童性发育疾病的分型,具有快速检测的优越性,与常规G显带相结合分析有助于儿童性发育疾病的初步诊断。     

郑州地区2小时～14岁儿童先天性智力低下细胞遗传学研究

目的　通过对患儿染色体核型进行分析 ,了解各种异常染色体对先天性智力低下 (MR)造成的影响。方法　运用常规外周血高分辨、脆性X检测技术 ,制备中期细胞染色体 ,采用C、G、Q、R带多种显带方法 ,进行染色体分析。结果　在 1171例MR中发现染色体异常 345例 ,占 2 9.4 6 % ,常染色体数目及结构异常 30 2例 ,占异常病例的 87.5 4 % ,性染色体数目及结构异常 4 3例 ,占 12 .4 6 %。结论　染色体异常是引起小儿MR的重要病因 ,通过产前诊断并及时终止妊娠是防止MR出生的有效方法之一     

身材矮小女童969例的染色体核型分析

目的 分析女童身材矮小细胞遗传学方面的原因.方法 对969例身材矮小的女童做外周血染色体检查,采用常规外周血淋巴细胞培养,G显带,油镜下每例计数30个中期分裂相,分析5个核型,对异常核型增加核型分析数,进行核型分析.结果 发现异常核型264例,异常率为27.2％.其中45X77例(29.1％),45X/46XX嵌合76例(28.8％),45X/46Xi( Xq)27例(12.2％),46Xi( Xq) 20例(7.6％),46XX/47XXX 9例(3.4％),46X,del( Xp)7例(2.6％),45 X/46XY 6例(2.2％).结论 染色体异常是女童身材矮小的一个重要原因,应引起临床医师的高度重视,可作为常规检查.     

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.     

矮身材女性患儿染色体核型分析及其临床意义

目的　了解女性矮身材与染色体核型之间的关系。方法　对 2 6 1例矮身材的女性患儿常规制备外周血淋巴细胞G显带标本 ,进行染色体核型分析 ,必要时做C带、高分辨G显带分析。根据临床表现将患儿分为两组 :A组为单纯生长落后组 92例 ;B组为疑诊Turner综合征组 16 9例。结果　两组的染色体核型 ,A组 :4 6 ,XX(n =82 ) ;4 5 ,X(n =5 ) ,4 5 ,X/ 4 6 ,XX(n =1) ;4 5 ,X/ 4 6 ,X ,i(Xq) (n =1) ;4 5 ,X/ 4 6 ,X ,mar(n =1) ;4 6 ,X ,del(X) (q12 ) (n =1) ;4 6 ,XX ,t(5 ,11) (5p11p ;5 q11q) (n =1)。B组 :4 6 ,XX(n =75 ) ;4 5 ,X(n =4 8) ;4 6 ,X ,i(Xq) (n =16 ) ;4 5 ,X/ 4 6 ,X ,i(Xq) (n =6 ) ;4 5 ,X/ 4 6 ,X ,mar(n =7) ;4 5 ,X/ 4 6 ,XX(n =2 ) ;4 5 ,X/ 4 6 ,X ,r(X) (n =1) ;4 6 ,XX/ 4 6 ,X ,i(Xq) (n =1) ;4 5 ,X/ 4 6 ,X ,del(X) (q12 ) (n =1) ;4 6 ,XX/ 4 6 ,X ,del(X) (q2 2 q2 4 ) (n =1) ;4 6 ,X ,del(Xp) (n =4 ) ;4 6 ,X ,del(Xq) (n =2 ) ;4 6 ,X ,dir　dup(X) (q2 3→q2 5 ) (n =1) ;4 7,XXX(n =3) ;4 5 ,X/ 4 6 ,XY(n=1)。A、B两组患儿的年龄及染色体核型异常者的年龄比较有显著性差异。结论　①矮身材的女性患儿染色体异常多见 ,故对矮身材的女孩应常规做染色体核型分析 ,以排除染     

The Pallister-Killian syndrome in a child with rare karyotype—a diagnostic problem

The Pallister-Killian syndrome is a clinically recognizable syndrome, usually due to a tissue-specific mosaicism for a 12p isochromosome [i(12p)]. We report a rare case of Pallister-Killian syndrome with 12p mosaicism, tetrasomy/trisomy/disomy in fibroblasts and trisomy/disomy in lymphocytes. Marker chromosomes were investigated with conventional cytogenetic techniques and fluorescent in situ hybridisation (FISH). The karyotype was established as: mos47,XX,+12p/47,XX,+i(12p)/46,XX. The cytogenetic result of the extra mosaic 12p presented in lymphocytes suggested the diagnosis of trisomy 12p, although, in combination with clinical manifestations, the Pallister-Killian syndrome was considered and confirmed by the cytogenetic analysis of fibroblasts.     

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。     

Congenital monoblastic leukemia cutis. A case report with chromosomal abnormality: del (10p)

Congenital monoblastic leukemia cutis is a rare disorder. We report an infant who developed infiltrative skin lesions by 2 weeks of age, which, when biopsied at 4 1/2 months of age revealed a monoblastic infiltrate. Blasts in the peripheral blood were not seen until 1 week before her death at 8 months of age. Chromosomal analyses of her bone marrow showed an abnormal clone of cells with a 46,XX,del(10)(p12) karyotype. Although chromosome 10 is rarely involved in hematologic malignancies, abnormalities of this chromosome within the region 10p11-10p13 have now been shown in four of 10 reported cases of congenital monoblastic leukemia.     

A case with dicentric translocation between chromosome 9 and 18: Confirmation by fluorescent in situ hybridization on metaphase spread

A female child with dicentric translocation between chromosome 9 and chromosome 18 presented non-specific minor anomalies with laryngomalacia. Chromosomal analyses were performed by the G-banding method and a fluorescence in situ hybridization (FISH) technique with a specific probe for the centromeric region of chromosome 18 and the painting probe for the chromosomes 9 and 18. Her full karyotype was confirmed as 45, XX, tdic (9;18)(p24;p11). This is the first case of dicentric translocation between chromosomes 9 and 18. The FISH technique is an important tool in chromosome diagnostics.     

一例13号环状染色体综合征患儿的临床及遗传学分析

患儿,女,5个月,因生长发育迟缓就诊,体格检查发现体格发育落后,特殊面容（小头畸形、眼距宽、耳位偏低、鼻梁扁平、短人中）以及一侧小阴唇缺失。外周血染色体核型为46,XX,r（13）（p11q33）[82]/45,XX,-13[10]/46,XX,r（13;13）（p11q33;p11q33）[8];微阵列比较基因组杂交（aCGH）检测显示13q11q33.2区域和13q33.2q34区域分别有87.5 Mb的重复和8.2 Mb的缺失;荧光原位杂交（FISH）显示13号环状染色体长臂末端缺失。诊断为13号环状染色体综合征。该综合征临床表型多变,主要与染色体区带中遗传物质丢失的数量、部位以及不同核型嵌合比例不同等密切相关。     

A Mosaic Case of Isodicentric Chromosome 18

A case of mosaicism of isodicentric chromosome 18 is reported. Dicentric chromosome 18 occurs rarely and only five cases of isodicentric chromosome 18 have been documented. A high resolution banding method revealed that the karyotype of the patient was mos 46,XX/46,XX idic(18)(pter→q21.3::q21.3→pter), and the ratio of normal and abnormal clones was 1:1. The clinical manifestations, resembling those of trisomy 18 syndrome, were affected by both partial trisomy 18pter→q21.3 and partial monosomy 18q21.3→qter.     

Monozygotic twin discordant for Down syndrome: mos 47,XX,+21/46,XX and 46,XX

Monozygotic twins, developed from a single zygote, are almost identical in clinical phenotype and concordant karyotypes. Monozygotic twins with discordant karyotypes are thought to be quite rare. Here, we report monochorionic-diamniotic twins discordant for Down syndrome. On findings of prenatal ultrasonography, nuchal translucency thickness was different between twins, and suggested that one of the twins was at high risk for having chromosomal abnormalities including Down syndrome. The twins were monochorionic-diamniotic; therefore, chorionic villi sampling of the common placenta was performed. The karyotype of the chorionic villi cells was 46,XX, and pregnancy was maintained. After delivery, dysmorphic clinical features suggesting Down syndrome were found in one of the twins, while the other twin showed a morphologically normal appearance. Karyotypes of peripheral blood leukocytes were repeatedly normal in the dysmorphic twin; however, the karyotype of skin fibroblasts from the dysmorphic twin indicated Down syndrome mosaicism; 47,XX,+21[99]/46,XX[2]. The karyotype of skin fibroblasts from the morphologically normal twin was 46,XX. Monozygosity of the twins was confirmed by a short tandem repeat analysis using 16 polymorphic markers. A mitotic nondisjunction followed by the twinning would explain the discordant karyotypes between monozygotic twins.     

Familial small supernumerary marker chromosome (sSMC) (14)(:P11–q11:)In a child with translocation down syndrome

We report a case of familial small supernumerary marker chromosome (sSMC)in a child with translocation Down syndrome (DS)and mother. The GTG-banded chromosomal analysis of DS child revealed 47,XY,+21,+mar and mother karyotype was 47,XX,+mar. The GTG-banded sSMC had a similar morphology of small acrocentric chromosomes. Fluorescence in situ hybridization (FISH)evaluation of sSMC using centromere probes(13/21,14/22,22)confirmed sSMC as derivative chromosome 14. The sSMC was not specifically stained with whole chromosome paint and arm-specific probes for chromosome 14;thus it has been described as der(14)(:p11–q11:).The phenotypic changes were not evident, may be due to trisomy condition in the child or the sSMC contain repetitive sequences.