产前诊断12p部分三体综合征一例

患者 女，39岁，孕19周。10年前曾生育过染色体异常患儿。患儿的染色体核型为：46，XY，-7，＋der（7），t（7；12）（p22；p11）mat。母亲核型为：46，XX，t（7；12）（p22；p11），父亲核型正常。     

产前诊断18号部分三体综合征一例

患者女，28岁，孕23周，曾有两次早期自然流产史，孕期无不良因素接触史，夫妇双方非近亲婚配，双方表型和智力正常。此次患者怀孕16周时做产前筛查，结果为18三体高风险，风险值为1／10。患者于妊娠23周进行羊膜腔穿刺，羊水细胞培养，经制片，G显带计数50个分裂相，镜下分析10个分裂相，胎儿染色体核型为46，XX，-4，＋der（4），t（4；18）（q12；p14）mat。夫妻双方染色体核型检查，丈夫核型正常，其妻核型为46，XX，t（4；18）（q12；p14），胎儿异常染色体片段来源于母亲染色体平衡易位。     

9p三体误诊为21三体一例

病例：一对年轻夫妇来做遗传咨询：有一个4岁智力低下的男孩,在某医院诊治时,染色体检查为21三体综合征,现在想再生育,应做哪些检查或治疗？将患儿当时做的“染色体检查报告”和“染色体核型分析报告”拿给我们看,核型分析报告中的21号染色体三个排列中,其中一个比另两条21号大,且带纹显示与21号的深染区相反,我们认为此多出的一条不是21号染色体。在对夫妇进行咨询和全面检查后,未发现各系统异常,非近亲结婚,也无相应的家族史。建议他们将孩子带来,三人同时进行染色体检查,根据检查结果,再给予他们生育方面的指导和建议。     

6p部分三体综合征的临床及细胞遗传学分析

６ｐ部分三体综合征的临床及细胞遗传学分析王文强，霍满鹏６ｐ部分三体综合征（６ｐｐａｒｔｉａｌｔｒｉｓｏｍｙｓｙｎｄｒｏｍｅ）已被证实是由于６ｐ１１到６ｐ２５→６ｐｔｅｒ区段重复所致，表现出多种先天性异常或畸形的一类染色体病，１９７１年由Ｔｈｅｋｃｌｅ...     

21例伴有4号染色体三体细胞的急性白血病的分析

目的探讨伴有4号染色体三体细胞的急性白血病（acute leukemia，AL）的临床和实验室特点。方法对21例伴有4号染色体三体细胞的AL患者的临床和实验室资料进行回顾性分析。21例均采用骨髓细胞直接法或短期培养法制备染色体，用R显带技术进行核型分析；其中5例核型分析揭示t（8；21）易位者，采用AMLl／EqO双色探针和间期荧光原位杂交技术进行AMLl／ETO重排检测；应用SpectrumGreen标记的4号着丝粒探针，对其中13例AL患者进行荧光原位杂交检测。结果21例AL中2例为继发性白血病，其余均为原发性白血病。4号染色体三体异常主要见于AML-M2（9／21例），21例中7例为单纯4号染色体三体，14例同时伴有其他异常，以t（8；21）最常见（8／14例）；临床上16例初诊白细胞计数大于10×10^9／L；15例有不同程度的肝、脾和淋巴结肿大；进行免疫表型分析的15例患者中6例为髓系和淋系抗原共表达，11例有CD34表达。双色荧光原位杂交研究揭示其中5例核型分析显示t（8；21）者均有AMLl／EqO重排，单色荧光原位杂交也证实14例为4号染色体三体阳性。结论伴有4号染色体三体异常的急性白血病有着独特的临床和实验室特点，其预后不良。     

亲子鉴定中检出21三体综合征一例

我们在亲子鉴定案例中检出1例21三体综合征(Down’s syndrome)，其3个位于21号染色体的短串联重复序列(short tandem repeat,STR)基因座图谱均表现为3个峰(或3条带)．现报道如下。     

频谱染色体核型分析技术诊断部分22三体一例

传统的细胞遗传学技术能诊断绝大多数染色体疾病，但由于技术的局限性，也存在一些诊断的盲区，如对一些marker染色体、复杂易位或微小易位、缺失异常就无法用常规的G带或者B带来诊断。     

染色体11q部分三体综合征的细胞遗传学分析

1972年Rott等首次报道了1例染色体11q部分三体综合征[1].11q部分三体综合征患者多数源自于携带者,并且以平衡易位携带者最为常见.最近,我室发现了1例罕见的来源于臂间倒位携带者的11q部分三体综合征患儿,其染色体核型经医学遗传学国家重点实验室医学遗传学国家培训中心鉴定为世界首报核型,现报告分析如下.     

嵌合型8-三体综合征一例并文献复习

目的 总结8-三体综合征患者的临床表现。方法 采用常规方法进行外周血培养,制备染色体标本,G显带染色体核型分析,并结合文献分析此类患者的临床表现。结果 该例患儿常规核型分析结果为47,XX,+8[10]/46,XX[10],8-三体的嵌合比例为50%,患者身材矮小,肋骨外翻。结论 8-三体综合征为较少见核型异常,临床表现为包括特殊面容、轻度发育迟缓、轻到中度智力低下、发育异常、癫痫、语言障碍等。     

染色体部分三体两家系

病例：家系1,先证者,男,30岁,其妻妊娠3次,均在孕6个月左右B超发现胎儿复杂型先天性心脏病后引产,最近1次于我院妇产科引产后取脐带血行染色体核型分析。夫妇体健,表型、智力均正常,非近亲婚配,孕期无有害物质及放射线接触史。外周血染色体G显带核型分析：46,XY,t（4;6）（4 qte→r4 p 14∷6 p 25→6 pter;6 qte→r6 p 25∷4 p 14→4 pter）,见图1 a。     

A fourteen years follow-up of a case of partial trisomy 12q and monosomy 12p recombinants of a familial pericentric inversion of chromosome 12: clinical, cytogenetic and molecular observations

Partial trisomy 12q and monosomy 12p lead to multiple malformation syndromes. Only four cases were previously reported with the association of these two aneusomies resulting from a familial pericentric inversion of chromosome 12. We report on the clinical, cytogenetic and molecular findings in a boy with an unbalanced karyotype which resulted from a familial pericentric inversion of chromosome 12. The patient was evaluated at birth and followed up until 14 years of age. He showed severe mental retardation, seizures, and dysmorphic features related both to a trisomy 12q and a monosomy 12p. Chromosome breakpoint BAC-FISH mapping revealed that the rec(12) chromosome had a terminal deletion of a 6.7Mb region extending from 12pter to 12p13.31 and a duplicated region of 19.8Mb extending from 12qter to 12q24.13. The findings from the case reported here emphasize the occurrence of some consistent clinical features and illustrate the deficiencies associated with the recombinants from the inversion inv(12)(p13.31q24.13)mat.     

Partial trisomy 3p syndrome

Two cousins with an unbalanced chromosome translocation (partial trisomy 3p) are described. Both children have a clinically recognizable syndrome of square facies with prominent cheeks, narrow bitemporal regions, psychomotor retardation and congenital heart disease. Extended family studies showed one other individual proven to have partial trisomy 3p karyotype, two retarded individuals with congenital heart disease who probably had it, and 14 balanced carriers of the translocation t(1;3)(q43;p21). This report confirms the characteristic clinical appearance of affected individuals and emphasizes the frequency in which congenital heart disease is the presenting feature of partial trisomy 3p. An additional 22 cases of partial 3p trisomy are reviewed.     

Clinical delineation of a patient with trisomy 12q23q24

Trisomies of 12q23q24 have been described rarely in literature. Only a few case-reports have been published so far almost exclusively reporting on neonates or young infants. We present a 16-year-old patient with a trisomy of 12q23.3q24.3. Full phenotypic evaluation at this age comprised: severe growth retardation, developmental delay, intellectual disability and characteristic facial dysmorphisms. Initially, in the proband an insertion was cytogenetically mapped at chromosome 16: der(16)dir ins(16; 12)(q12.1; q24.11q24.31). The mother appeared carrier of a balanced insertion. Subsequent SNP-array analysis in the proband revealed a 16.3 Mb gain of 12q23.3 → 12q24.31. The clinical and molecular findings in this patient are compared with previous literature on cases with overlapping isolated 12q trisomies. The common phenotype observed consists of severe growth retardation, intellectual disability and characteristic facial features with hypertelorism, flat nasal bridge, down-turned mouth and poorly lobulated/low set ears. In addition, pediatric follow up into adolescence showed feeding difficulties requiring gastric tube feeding, recurrent otitis media, progressive contractures of joints and genito-renal problems, speech, communication and behavioral problems. These symptoms should be taken into account in the care and management of children with this condition.     

Deletion of the short arm of chromosome 20

A de novo deletion of the short arm of chromosome 20--del (20) (p11) or (p11p13)--is described in a child with psychomotor retardation and multiple congenital anomalies.     

荧光原位杂交技术及染色体核型分析在罗伯逊易位型21-三体检测中的应用

目的 通过对孕妇羊水进行染色体核型、荧光原位杂交(fluorescence in situ hybridization,FISH)分析,探讨两者联合检测在诊断罗伯逊易位型21-三体中的应用价值.方法 为2010年1月至2011年12月进行产前诊断的孕妇抽取羊水,经体外细胞培养后进行G显带染色体核型分析.对发现的5例罗伯逊易位采用FISH检测间期细胞13、18、21及X/Y的染色体数目,并分析孕妇及其丈夫外周血染色体核型.结果 两个胎儿父母外周血染色体核型正常,其中一个胎儿羊水染色体核型为46,XY,rob(21;21)(q10;q10),FISH检测提示其为21-二体,另一个胎儿核型为46,XY,rob(14;21)(q10;q10),FISH检测证实其为21-三体.另外3个胎儿母亲外周血染色体核型分别为45,XX,rob(14;21)(q10;q10)、45,XX,rob(15;21)(q10;q10)、45,XX,rob(21; 22) (q10; q10),其羊水染色体核型分别为46,XX,rob(14;21)(q10;q10)、46,XY,rob(15;21) (q10;q10)、46,XX,rob(21;22)(q10;q10).FISH检测证实其均为21-三体.结论 染色体核型分析结合FISH检测有助于明确罗伯逊易位型21-三体的诊断,但FISH检测同源罗伯逊易位型21-三体征有一定局限性.     

A case of de novo trisomy 12p syndrome

A case of pure 12p trisomy was discovered in a 14-year-old boy during a cytogenetic survey of Egyptian students attending a school for mentally retarded children. The patient had a normal birth weight but later showed developmental delay. Clinical examination at 14 years of age revealed a high bulging forehead, broad and flat nasal bridge, large mouth with everted lower lip, folded upper ear helix with protuberant antihelix, pectus excavatum, undescended testes, flat feet, generalized hypotonia and moderate mental retardation. Chromosomes analyzed from blood lymphocytes showed an enlarged short arm with an additional band on one of the no. 12 chromosomes. The duplicated chromosomal material extended from 12pter----p12.2, including the LDH-B locus, which showed a gene-dosage effect. This extra chromosomal material arose de novo by tandem duplication. The parents' chromosomes were normal.     

广东部分地区376例遗传咨询者染色体21-三体综合征分析

目的了解广东地区临床1岁以内婴幼儿的21-三体综合征的发生及分布情况.方法本文通过遗传咨询筛查,和进行G显带染色体研究,对在2004年1年内376例来自广东省各地区临床的1周岁以内的婴幼患儿进行检查.结果检出异常核型113例,总的异常率为30.05%.其中21三体95例,占总异常的84.07%,男性21三体60例,女性21三体35例,是婴儿染色体异常的主要原因.结论21三体患儿的出生给家庭和社会带来沉重的负担和许多不良影响.本文提出,整个社会都应大力提倡通过产前筛查(孕早期AFP、uE3、β hCG组合项目筛查)、产前诊断(脐血、羊水等染色体检查)及选择性人工流产的方法杜绝患儿出生.     

Anatomy of trisomy 12

Trisomy 12 is a rare aneuploidy and fetuses with this defect tend to spontaneously abort. However, mosaicism allows this anomaly to manifest itself in live births. Due to the fact that mosaicism represents a common genetic abnormality, trisomy 12 is encountered more frequently than expected at a rate of 1 in 500 live births. Thus, it is imperative that medical practitioners are aware of this aneuploidy. Moreover, this genetic disorder may result from a complete or partial duplication of chromosome 12. A partial duplication may refer to a specific segment on the chromosome, or one of the arms. On the other hand, a complete duplication refers to duplication of both arms of chromosome 12. The combination of mosaicism and the variable duplication sites has led to variable phenotypes ranging from normal phenotype to Potter sequence to gross physical defects of the various organ systems. This article provides a review of the common anatomical variation of the different types of trisomy 12. This review revealed that further documentation is needed for trisomy 12q and complete trisomy 12 to clearly delineate the constellation of anomalies that characterize each genetic defect. Clin. Anat. 29:633–637, 2016. © 2016 Wiley Periodicals, Inc.     

Tetrasomy for the short arm of chromosome 12 with accessory isochromosome (+i(12p)) and a marked LDH-B gene dosage effect

A fetus with tetrasomy for the short arm of chromosome 12 due to a de novo accessory isochromosome i(12p) is described. Involvement of the 12p in this chromosome aberration was suggested by banding analysis and substantiated by detection of a marked increase of LDH-B in the fetal fibroblasts. The syndrome shown by this fetus includes many of the minor anomalies described for live-born patients with partial trisomy 12p, and in addition malformations including brachymelia, anal atresia and double kidneys.     

The dermatoglyphic pattern of the trisomy 10p syndrome

Dermatoglyphic findings are reported for six members of a family in which two patients have partial trisomy for the short arm of chromosome 10(p13→pter) and there are two unaffected carriers of the balanced translocation t(5;10)(p15;p13). The patterns are compared with those of nine other published cases of trisomy 10p. The following dermatoglyphic features appear to be characteristic for the trisomy 10p syndrome: frequent whorls and a high total ridge count on the finger prints and on the palms, C-lines terminating in space 11 (2nd interdigitum), B-lines terminating in space 9 (3rd interdigitum), axial triradii t", high atd angles, abnormal creases on the palms and soles, and general dysplasia of the papillary ridges.