21号环状染色体的细胞遗传学分析

目的通过对1例21号环状染色体嵌合体患者的细胞遗传学分析,探讨21号环状染色体的形成原因,临床表型与染色体区带及嵌合比例的关系。方法应用染色体常规标本、G显带、C显带技术对21号环状染色体进行识别与区带定位。结果患者核型为mos46,XX,r（21）（pllq22）[91]／45,XX,-21[5]／46,XX,dicr（21;21）（pllq22;p11q22）[4]。结论环状染色体断裂位点在21pll和q22,21号环状染色体综合征的临床表现与核型嵌合比例及21q末端缺失的多少相关,女性不孕可能与21q22片段的缺失相关。     

一例21号环状染色体综合征的细胞遗传学和表型定位分析

目的通过对1例21号环状染色体综合征患者的细胞遗传学分析，探讨21号环状染色体的形成原因，临床表型与染色体区带的关系。方法应用染色体G带、C带、N带、高分辨显带和荧光原位杂交技术对21号环状染色体进行识别与定位。结果患儿双亲核型正常，患儿核型为46，XY，r（21）[91]／46，XY，r（21；21）（p11q22．3；p11q22．3）[5]／45，XY，-21[4]。结论21号环状染色体综合征的临床表现与21q末端缺失的多少相关，男性性别发育异常可能与21q22．3片段的缺失相关。     

13号环状染色体合并长臂部分缺失嵌合核型1例的细胞遗传学分析

目的通过对1例13号环状染色体合并长臂部分缺失嵌合核型患者的遗传学分析,探讨13号环状染色体异常与临床表型的关系。方法应用细胞遗传学技术,对1例临床表现为发育不良的7岁女孩进行外周血染色体核型分析,并结合临床资料进行遗传学分析。结果患儿染色体异常为新发突变,外周血染色体核型为mos 46,XX,r(13)(p13q34)[218]/46,XX,del(13)(q14)[86]/45,XX,-13[41]/46,XX,dic r(13;13)(p13q34;p13q34)[20]/47,XX,-13,+dic r(13;13)(p13q34;p13q34)×2[6]。遗传学分析显示患儿13号染色体存在遗传物质的丢失与重复,不同核型嵌合比例存在差异。结论 13号环状染色体综合征临床表型多变,与染色体遗传物质丢失或增加、环状染色体的不稳定性以及不同核型嵌合比例不同等密切相关。本例患者临床表现与其复杂的染色体嵌合核型有关,对此类患者的后期临床应密切关注。     

9号环状染色体综合征的荧光原位杂交分析

目的 对1例9号环状染色体综合征患儿进行细胞分子遗传学分析,探索9号环状染色体与临床表型的关系.方法 采用染色体G显带核型分析和TelVision 9p探针和TelVision 9q探针进行双色荧光原位杂交,识别和定位1例9号环状染色体患儿.结果 患儿核型为45,X,-9/46,XX,r(9)(p24q34)/46,XX,r(9;9)(p24q34;p24q34)(4/92/4).双色荧光原位杂交显示9号环状染色体上没有杂交信号,提示9号环状染色体短臂末端缺失片段至少有115 kb,长臂末端缺失片段至少有95 kb.与其它报道的环状9号染色体综合征、9号染色体短臂和长臂部分单体综合征相比,本例患者兼有环状9号染色体综合征的临床特征以及9号染色体短臂和长臂部分单体综合征的一些特征.结论 由于缺失的断裂点之间亚显微结构的不同、环的不稳定性、基因与表型相互作用以及胎儿环境条件的不同等原因,具有相同断裂点的9号环状染色体综合征患者可以有不同的临床表型,单倍基因剂量不足对临床表型发挥了重大作用.     

一例嵌合型环状13号染色体病例报道和文献回顾

13号环状染色体综合征临床中通常表现为发育迟缓或智力低下等先天异常。本文报道了1位由于嵌合型13号环状染色体造成的智力低下的5岁女童。患儿外周血染色体核型分析为mos 46,XX[35]//45,XX,-13[10]/45,XX,t(13;13)(p13q34)[12]/46,XY,r(13)(p13q34)[22]/46,XX,del(13)(q31-qter)[13]。我们比较本病例与国外报道的r(13)(p13q34)型环状13号染色体综合征临床特征,提示13号环状染色体综合征患者临床特征有很大的变化。     

5例环状染色体综合征的产前诊断和表型分析

目的通过对5例环状染色体综合征患者进行细胞遗传学分析,探讨高分辨率G显带核型分析和微阵列比较基因组杂交两种方法对环状染色体的诊断优势,并探讨5例环状染色体综合染色体缺失片段和定位于其中的基因与临床表型的关系。方法 2017年就诊于深圳市妇幼保健院的5例环状染色体综合征病例纳入研究。用染色体G带高分辨显带和微阵列比较基因组杂交技术对5例环状染色体进行识别与定位。结果病例1羊水染色体核型结果:45,XN,-18[13]/46,XN,r(18)(p11.2q22.3)[47],羊水微阵列比较基因组杂交结果:arr[GRCH37]18q22.3q23(70,063,358-78,013,728)x1;18p11.32p11.23(136,227-8,002,810)x1;18p11.23p11.22(8,013,797-8,877,061)x3。病例2脐血染色体核型结果:46,XN,rec(21)r(21q)dup(21q)(q11.2-q22.2)?,脐血微阵列比较基因组杂交结果:arr[GRCH37]21q11.2q22.3(15,016,486-47,044,951)x2～4;32MB.21q22.3(47,052,734-48,093,361)x1。病例3脐血染色体核型结果:45,XY,-21[14]/46,XN,r(21)[86],脐血微阵列比较基因组杂交结果:arr[GRCh37]21q11.2q22.3(15016486_47632178)x3[0.47];21q22.3(47632178_48093361)x1。病例4羊水染色体核型结果:46,XX,r(4)(p16q35),羊水微阵列比较基因组杂交结果:arr[GRCH37]4p16.3p16.1(68,345-8,721,580)x1;4q35.2(190,602,426-190,957,460)x1。病例5羊水染色体核型结果:mos45,X[46]/46,x,r(x)(p22.3q21.1)[34],羊水微阵列比较基因组杂交结果:Xq21.1q28(82119329_155233098)x1;Xp22.33p22.32(168551_5677733)x1;Xp22.32q21.1(5677733-82119329)x1[0.4]。结论 (1)环状染色体综合征患儿的临床特征与染色体区带缺失重复部位和大小相关。(2)G显带核型分析和微阵列比较基因组杂交诊断环状染色体各有优势:第一传统的G显带核型分析首先可判断是否存在嵌合的染色体核型;第二即使微阵列比较基因组结果提示染色体仅有长臂或短臂的缺失,也不能排除环状染色体的可能,亦需要传统的G显带染色体核型共同分析;第三微阵列比较基因组杂交能够精确基因组微小缺失和重复,利于基因组拷贝数变异与临床表型分析。因此联合G显带核型分析和微阵列比较基因组杂交对于环状染色体的诊断和遗传咨询具有指导意义。     

46,XX,t(10;13)伴习惯性流产一例

患者　女 ,2 8岁 ,因自然流产 3次就诊。两次流产发生在妊娠 4 0余天 ,1次发生于妊娠 3个月。孕期无明显感染史 ,亦无药物、X线等有害因素接触史。查体表型及智力正常。妇科检查正常。非近亲婚配 ,配偶体健 ,家族中无类似病史。细胞遗传学检查 :取外周血常规制备染色体标本 ,G显带 ,镜下计数 5 0个中期分裂相 ,分析 5个核型 ,结果患者核型为 4 6 ,XX,t(10 ;13)(10 pter→ 10 q11∷ 13q2 2→ 13qter;13pter→ 13q2 2∷ 10 q11→10 qter)。其丈夫及父母核型均正常。讨论　该患者为染色体平衡易位携带者 ,因无染色体片段的增减 ,其表型和智力…     

46,XX,ins(15;13)伴习惯性流产一例

患者　女 ,2 6岁 ,婚后怀孕 2次均于 70 + 天自然流产。孕期无接触有害物质。夫妻表型及智力正常 ,非近亲结婚。其父母表型、智力正常 ,自诉其母自然流产 1次。细胞遗传学检查 :同时取夫妇外周血淋巴细胞培养 ,常规制片、G显带 ,各分析 3 0个中期分裂相 ,患者核型为 46,XX,ins(15;13 ) (15pter→ 15q2 1∷ 13 q3 2→ 13 q2 2∷ 15q2 1→ 15qter;13 pter→ 13 q2 2∷ 13 q3 2→ 13 qter)。其丈夫核型正常 ,其父母拒绝检查。　　讨论　这是一例极为罕见的非同源衍生染色体及中间缺失染色体携带者。因本身无遗传物质的丢失 ,故表型和智力正常…     

母源性46,XX,der(13)t(11;13)(q23;p12)染色体非平衡易位的细胞遗传学分析

目的 对1例面容特殊,头发、眉毛稀疏,鼻梁低平,低位耳,眼距过宽,腭弓高,嘴角下垂,颈短,通贯掌,全身皮肤薄而光滑,先天性心脏病表现的患儿进行细胞遗传学分析,探索临床表型与细胞遗传学因素的相关性。方法 应用G显带染色体核型分析技术对患儿及其父母外周血进行细胞遗传学检测。结果 G显带染色体核型分析显示患儿母亲核型为46,XX,t(11;13)(q23;p12),患儿父亲核型为46,XY,患儿核型为46,XX,der(13)t(11;13)(q23;p12)mat。患儿携带母源性染色体非平衡易位,为11q23→qter片段重复。结论 患儿的临床表型与11号染色体长臂部分片段重复有关,通过染色体家系调查明确了患儿病因,也发现了其母亲既往的复发性流产的根源,对该家庭下一次生育的优生优育指导具有重大的临床意义。     

46,XX,t(13;22)伴习惯性流产一例

患者　女 ,2 9岁 ,结婚 7年 ,妊娠 5次 ,均于孕两个月时自然流产。查体 :身高 16 0 cm,体重 5 0 .5 kg。表型、智力正常 ,妇科检查正常。实验室检查 :肝功能、肾功能、电解质正常 ;甲状腺功能正常 ;性激素水平正常。细胞遗传学检查 :取外周血常规培养 ,染色体制备 ,G显带分析 ,患者核型为 :46 ,XX,t(13;2 2 )(13pter→ 13q34∷ 2 2 q11→ 2 2 qter;2 2 pter→ 2 2 q11∷ 13q34→13qter) ,丈夫核型正常 ,其他家系成员拒绝做染色体检查。家系调查 :患者系第 1胎足月顺产 ,其母生育 3胎 ,一兄一妹均已正常生育 ,其父母表型正常 ,非近亲婚配 ,…     

Interstitial deletion of the short arm of chromosome 1: attempt to establish a clinical phenotype (46,XX,del (1)(p22p32))

A girl with a de novo interstitial deletion of the short arm of chromosome 1 (46,XX,del (1)(p22p32) is described with moderate developmental delay and minor phenotypic abnormality. These clinical manifestations are compared to previously reported patients with interstitial deletion of chromosome 1, in an attempt to identify a clinical phenotype which seems quite different from the syndrome linked to more terminal deletion of chromosome 1p, and perhaps from more proximal 1p deletion phenotype.     

Child with multiple congenital anomalies and mosaicism 46, XX/46,XX,del (14)(q32.3)

We report on a female infant with multiple congenital anomalies and severe developmental delay in association with a rare, terminal deletion of chromosome 14 [karyotype:mosaic. 46,XX/46,XX del (14) (q32.3) = 36%:64%]. © 1992 Wiley-Liss, Inc.     

Characterization of a de novo 48,XX, + r(X), + r(17) by in situ hybridizatio in a patient with neurofibromatosis (NF1)

We describe a patient with familial neurofibromatosis (NF1), short stature, developmental delay, and a de novo chromosome abnormality. In sity hybridization was done using chromosome specific centromere probes to characterize the karyotype as 46,XX/47, XX,+r(X) (p11q11)/47,XX,+r(17) (p11q11)/48, XX,+r(X) (p11q11),+r(17) (p11q11). The NF1 mutation, as well as each superunmerary ring chromosome, may have played a role in perturbing the normal developmenal process of this patient. © 1993 Wiley-Liss, Inc.     

Unbalanced translocation,t(18;21), detected by fluorescence in situ hybridization (FISH) in a child with 18q– syndrome and a ring chromosome 21

We report on an 8-year-old girl with minor anomalies consistent with 18q-syndrome and mild developmental delay. Initially cytogenetics showed a terminal deletion of chromosome 21 with mosaicism for a small ring chromosome 21 as the only apparent karyotypic abnormality: mos 45,XX,-21/46,XX,+r(21) (48%/52%). Further studies including FISH and DNA analysis demonstrated a denovo unbalanced translocation of chromosomes 18 and 21 with the likely breakpoints in 18q23 and 21q21.1. Most of 21q was translocated to the distal long arm of one chromosome 18, and this derivative 18 appeared to lack 18q23-qter. The small ring chromosome 21 [r(21)], present in only 52% of the patient's blood lymphocytes, did not appear to be associated with the abnormal phenotype since all 13 chromosome 21 markers that were examined in genomic DNA were present in 2 copies, and the phenotype of the patient was consistent with the 18q – syndrome. The Karyotype was reinterpreted as mos 45,XX,–18,–21,+der(18) t(18;21) (q23;q21.1)/46,XX, –18, –21,+der(18) t(18;21) (q23;q21.1), +r(21) (p13q21.1) (48%/52%). These results demonstrate the power of FISH in conjunction with DNA analysis for examination of chromosome rearrangements that may be misclassified by traditional cytogenetic studies alone. © 1993 Wiley-Liss, Inc.     

13q-/r(13) mosaicism.

A 2-month-old female infant with typical features of the 13q-syndrome was found to be a hitherto unreported mosaic consisting of 46,XX,del(13)(q22)-46,XX,r(13)(p13q22). Both of the 13q- and r(13) chromosomes were Ag N banding positive. Therefore, it was assumed that they had retained the satellite stalks. Two possible mechanisms were proposed for the genesis of the mosaicism. Firstly, the patients started with the 13q- chromosome, which then underwent breakage and reunion at both ends to form the r(13) chromosome. Secondly, the patients started with the r(13) chromosome, which reopened at or close to the joining point to form the 13q- chromosome.     

Transmission of ring chromosome 13 from a mother to daughter with both having a 46,XX, r(13)(p13q34) karyotype

Ring chromosomes are thought to be the result of breakage in both arms of a chromosome, with fusion of the points of fracture and loss of the distal fragments. Another mechanism of ring formation is believed to be the simple fusion of chromosome ends with preservation of telomeric and subtelomeric sequences. Ring chromosome 13 was first described in 1968 and its incidence estimated at 1 in 58,000 live births. Severe phenotypes associated with large deletions of 13q have been described as "ring chromosome 13 syndrome." Features of the "ring chromosome 13 syndrome" include mental retardation (often severe), growth retardation, microcephaly, facial dysmorphism, and hand, foot or toe abnormalities. We report on a case of a mother and daughter with r(13) and mild phenotypes. Our patient, IA, had chromosome analysis performed at about 4(1/2) years of age due to some developmental delay. This revealed 46,XX, r(13)(p13q34) karyotype with no loss of any chromosomal band. Her mother, EA, was subsequently found to have the same ring 13. IA's maternal grandmother had a normal karyotype while her maternal grandfather was unavailable for testing. Fluorescence in situ hybridization (FISH) analysis showed loss of a specific subtelomeric 13q region in r(13) in the mother. Clinically, IA had macular hyperpigmentation on the chin and mild delay in speech and fine motor skills. EA, 22 years of age, had mild short stature and borderline mental retardation. To our knowledge, this is the first report of a case of familial transmission of r(13). We compare phenotypes of our cases with those from other reported cases of r(13) and discuss the possible mechanism of formation of this ring chromosome.     

Trisomy 18q: 46, XX,13q+,t(13;18)(q32;q11) in a newborn associated with multiple congenital anomalies due to paternal reciprocal translocation, 46, XY,-13,+der(13)/t(13;18)(q32;q11)

A 20-day-old female neonate presented with multiple congenital anomalies, convulsions and failure to thrive. Karyotype analysis of the proposita revealed an unbalanced translocation, 46, XX,13q+,t(13;18)(q32;qll)pat resulting in partial trisomy 18q. Her father and a 5-year-old sister were phenotypically normal, balanced translocation carriers, 46, XY, -13, + der(13),t(13;18)(q32;qll) and 46, XX,-13,+der(13),t(13;18)(q32;qll), respectively. The case presented here is the second liveborn reported with trisomy 18q and is of interest from the point of view of the structural chromosomal aberration resulting in the manifestations of most features of trisomy 18 and some of 13q monosomy. The infant died due to convulsions at the age of 2 months.     

13号环状染色体综合征的临床及其细胞遗传学研究

本文对一例罕见的１３号环状染色体综合征患儿家系进行了外周血淋巴细胞培养、ＧＴＧ、ＣＢＧ、Ａｇ－ＮＯＲ显带和高分辨Ｇ显带等细胞遗传学研究，证实患儿核型为４５，ＸＸ，－１３／４６，ＸＸ，ｒ（１３）／４６，ＸＸ，ｒ（１３；１３）／４７，ＸＸ，２ｒ（１３；１３）（ｐ１１．２；ｑ３４），为一新生的、由４种不同异常细胞系组成的嵌合体，并对其产生原因及其与临床症状间的关系进行了讨论。     

Ring chromosome 10: 46,XX,r(10)(p15→q26)

Cytogenetic analysis of an 8-month-old Japanese girl with moderate retardation of physical development was performed and a ring chromosome 10, 46,XX,r(10)(p15→q26), was found. She had short stature, mildly stubby nose, antimongoloid slants, and moderately protruding ears. The extremities showed erythrocyanosis, oedema, and pigmentation. Lansky et al¹ was the first to describe ring chromosome 10 with a Turner-like phenotype. Only two other cases^{2 3} have been reported so far and little is known about this syndrome. This is the report of a fourth case.