50例儿童急性淋巴细胞白血病免疫分型、染色体核型及融合基因与预后分析

目的分析急性淋巴细胞白血病(ALL)免疫表型、染色体核型和融合基因在儿童ALL预后中的意义。方法收集2016年1月—2017年12月我院新发ALL患儿66例,除外未完成VDLP诱导即放弃治疗或转外院就诊者16例,50例纳入研究范围,其中男33例,女17例,平均年龄5. 4(0. 5～3)岁。采用FCM检测ALL细胞免疫表型,染色体R带核型分析,RT-PCR法检测43种ALL融合基因和33种Ph-like ALL相关融合基因,FISH检测MLL、BCR-ABL,TCF3-PBX1(E2A-PBX1),ETV6-RUNX1(TEL-AML1),MLPA法检测IKZF1缺失突变。结果 B-ALL 48例,T-ALL 2例。染色体核型正常38例,无核分裂相2例,异常10例。融合基因阳性15例:ETV6-RUNX15例,TCF3-PBX13例,BCR-ABL3例,MLL-AF4 2例,其它MLLr 2例。IKZF1缺失突变1例。死亡9例,其中无染色体核型及融合基因异常6例(B-ALL 4例,T-ALL 2例),染色体核型及融合基因异常2例[t (9; 22)(q34;q11)/BCR-ABL和t(4;11)(q21;q23)/MLL-AF4],染色体核型异常1例[46,XY,t(3;3)(q11;q28),del(4)(q21)]。结论白血病细胞免疫表型、染色体核型及融合基因检测对儿童ALL预后判断有重要意义。     

ETV6/RUNX1阳性儿童急性B系淋巴细胞白血病临床预后研究

目的探讨和验证ETV6/RUNX1融合基因在中国汉族B系急性淋巴细胞白血病(B-ALL)患儿中的阳性率及其对疾病预后的影响。方法回顾性分析2007年1月1日至2014年12月31日确诊并序贯治疗的B-ALL患儿经FISH技术检测的ETV6/RUNX1融合基因结果及其临床资料。结果共有723例B-ALL患儿,其中ETV6/RUNX1阳性B-ALL患儿151例,阳性率20.89%;在723例B-ALL患儿中91例患儿复发,其中ETV6/RUNX1阳性患儿复发10例,占复发患儿的10.99%。同时,在ETV6/RUNX1阳性患儿中,除1例在诊断后65 d复发,其余9例的复发时间均超过300 d,复发时间中位数为1 155 d(P_(25)~P_(75)=395.3~1 301.5);ETV6/RUNX1阴性患儿复发时间为484 d(P_(25)~P_(75)=259.0~1 017.5),两组复发时间差异无统计学意义(P=0.158)。对复发时间的分布区域分析发现,ETV6/RUNX1阳性患儿的复发期主要集中于临床化疗结束后,而阴性患儿的复发期主要集中于维持治疗期,两者的复发时间段分布差异有统计学意义(P0.001)。结论 ETV6/RUNX1在中国汉族儿童B-ALL中也是预后良好的标志之一。     

智力障碍儿童的亚端粒拷贝数变异检测

目的应用多重连接探针扩增技术(MLPA)检测亚端粒拷贝数变异,探讨遗传性智力障碍(ID)的发病机制。方法收集68例G-显带染色体核型分析结果正常的ID患儿,通过MLPA P036筛查亚端粒拷贝数变异。结果 68例患儿中检出亚端粒拷贝数异常者7例(10%),均为缺失突变,其中1例患儿涉及2个亚端粒的缺失变异,另1例患儿涉及4个亚端粒的缺失变异。结论亚端粒拷贝数变异是遗传性ID的重要病因;MLPA可作为研究遗传性ID患儿发病机制的经济、有效的方法。     

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.     

Y染色体拷贝数变异致性发育异常的临床和遗传学特点

目的探讨Y染色体拷贝数变异致性发育异常(DSD)患儿的临床表型和遗传学特点。方法回顾性分析郑州大学第一附属医院2018年1月至2022年9月收治的3例Y染色体拷贝数变异致DSD患儿的临床资料, 应用染色体核型分析、全外显子测序(WES)、低深度全基因组拷贝数变异测序(CNV-seq), 荧光原位杂交(FISH)和性腺组织病理活检技术对患儿进行临床分析和遗传学检测。结果 3例患儿就诊年龄分别为12、9、9岁, 均表现为身材矮小和性腺发育不良, 社会性别均为女。均为正常女童外阴, 例1伴脊柱侧弯, 余未见明显异常。3例患儿均报告为46, XY核型, WES未发现相关基因变异。CNV-seq确定例1为47, XYY, +Y(2.12), 例2为46, XY, +Y(1.6), 即Y染色体拷贝数增加。FISH最终确定2例患儿Yq11.2附近断裂后发生重组, 为携带拟双着丝粒Y染色体idic(Y)的嵌合体DSD。例1核型重新诠释为mos 47, X, idic(Y)(q11.23)×2[10]/46, X, idic(Y)(q11.23)[50], 例2为45, XO[6]/46, X, idi...     

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.     

联合应用多种分子遗传学技术阐述染色体芯片结果中潜在的结构异常

目的探讨拷贝数变异中潜在的结构异常。方法通过联合应用常规核型分析及FISH等分子生物学技术对4例存在拷贝数变异的智能障碍合并多发畸形的患儿进行鉴定,明确其染色体结构异常;进而对2个家系进行产前诊断及随访。结果 4例患儿经染色体芯片检测发现存在拷贝数变异,分别为16pter缺失/19qter重复、18pter缺失/18qter重复、13 qter缺失和3 p 13-14缺失。联合核型分析及FISH检测明确患儿潜在的结构异常,分别为1例染色体末端不平衡易位der(16)t(16p;19q)、1例倒位重复缺失invdup18p/del 18q、1例涉及随体易位(13qs)及1例父源性平衡插入重组导致3p间隙性缺失或重复。其中2例为家族性平衡重组导致,1例未确定但存在再发风险,1例为新发改变。其中2个家系于孕中期进行产前诊断,并随访证实与产前诊断结果一致。结论染色体芯片发现单纯拷贝数变异者可能存在潜在的染色体结构异常,联合应用多种技术可以明确潜在的结构异常,并提供准确的再发风险评估,从而指导疾病的产前诊断。     

儿童Pre-B急性淋巴细胞白血病和急性髓系白血病特异遗传亚型

目的总结儿童急性白血病(AL)特异遗传亚型的发生率和特征,为评估预后提供依据。方法对365例AL患儿进行骨髓染色体核型检测分析白血病细胞的遗传学特点,荧光原位杂交(FISH)检测特异基因及相应位点拷贝数变异。结果 175例前体B急性淋巴细胞白血病(Pre-B ALL)和54例急性髓系白血病(AML)存在特异亚型。在Pre-B ALL中,高超二倍体最常见(33%),t(12;21)/ETV6-RUNX1、t(4;11)/MLL重排、t(9;22)、t(1;19)和iAMP21占比分别为22%、5%、3%、7%和1%。在AML中,MLL重排最常见(18%),其中t(9;11)型占56%;BCR/ABL阳性1例,FISH证实是隐匿核型ins(22;9);t(8;21)、t(15;17)和inv(16)分别占12%、15%和8%。倍体水平显示ALL高超二倍体和AML超二倍体获得染色体方式为非随机性。值得注意的是特异亚型中的变异型和不同附加异常,如额外融合,del(9p),del(12p),dup(1q)和非整倍体等畸变。结论儿童Pre-B ALL和AML中特异遗传亚型的发生率与西方儿童相似,揭示遗传异质性可能有助于预后研究。     

急性淋巴细胞白血病患儿染色体改变及预后分析

目的应用染色体核型分析技术,探讨染色体核型异常对儿童急性淋巴细胞白血病(ALL)患儿预后判断的意义。方法回顾性分析2007年-2014年收治的初诊且伴染色体异常ALL患儿共65例的临床资料。结果 (1) 65例异常核型中单纯数目异常者21例(32%),单纯结构异常者14例(22%),数目及结构同时异常者30例(46%);(2)染色体结构异常者中,t(12;21)2例,t(9;22)6例,t(1;19)3例,t(4;11)2例。染色体数量异常者中,超二倍体核型最多,有29例(57%);(3)至随访截止时间,本组病例中生存49例,死亡11例,失访5例,复发9例。超二倍体和t(12;21)预后好,亚二倍体、t(1;19)和t(4;11)预后差;(4)本组患儿融合基因阳性22例,包括BCR/ABL6例,MLL2例,TEL/AML1 8例,E2A/PBX1 6例。与染色体结果比对,8例TEL/AML1仅测得2例t(12;21),6例E2A/PBX1中测得2例t(1;19),另外一例t(1;19)对应的融合基因阴性。结论 (1)本组ALL患儿染色体改变以数目及结构同时异常为主,数目异常中以超二倍体核型最为常见。(2)染色体核型与ALL预后有密切联系。(3)t(12;21)及t(1;19)染色体检测阳性率低于融合基因阳性率。     

IKZF1基因拷贝数异常在儿童BCR/ABL阴性B系急性淋巴细胞白血病中的意义

目的 了解BCR/ABL阴性B系急性淋巴细胞白血病(B-ALL)患儿IKZF1基因拷贝数异常情况,并分析IKZF1基因拷贝数异常与该部分患儿预后的相关性。方法 应用多重连接探针扩增(MLPA)技术检测180例初诊BCR/ABL阴性B-ALL患儿IKZF1基因拷贝数异常情况。根据有无IKZF1基因缺失将其分成两组:IKZF1缺失组和IKZF1正常组。回顾性分析IKZF1拷贝数缺失与BCR/ABL阴性B-ALL患儿预后的关系。结果 180例患儿中共有27例(15.0%)患儿发生了IKZF1缺失,其中IKZF1基因8个外显子全部缺失者4例,单纯1号外显子缺失者17例,4~7号外显子缺失者3例,2~7号外显子缺失者3例。IKZF1缺失组患儿初诊时白细胞水平及流式MRD-高危组患儿的比例明显高于IKZF1正常组;IKZF1缺失组患儿多发生在无特殊融合基因异常的BCR/ABL阴性患儿,且IKZF1基因缺失患儿易伴随出现11、8、5、7、21号等染色体的异常。Kaplan-Meier法分析显示,IKZF1缺失组无病生存率(DFS)明显低于IKZF1正常组(0.740±0.096 vs 0.905±0.034,P=0.002)。Cox法分析显示在排除了年龄、性别、初始WBC、初诊时脑脊液状态、泼尼松松试验反应情况、染色体核型后,IKZF1缺失仍不利于患儿的DFS(P结论 部分BCR/ABL阴性B-ALL患儿存在IKZF1缺失,IKZF1缺失为BCR/ABL阴性B-ALL患儿DFS的独立危险因素。     

RUNX1 ABERRATIONS IN ETV6/RUNX1-POSITIVE AND ETV6/RUNX1-NEGATIVE PATIENTS: Its Hemato-Pathological and Prognostic Significance in a Large Cohort (619 Cases) of ALL

A large-cohort study (619) of acute lymphoblastic leukemia (ALL) revealed an ETV6/RUNX1 (previously known as TEL/AML1) incidence of 18% in pediatric B-cell precussor ALL, indicating no geographical heterogeinity. Association of CD34-negative phenotype, peak incidence in the 3- to 7-year age group, and a comparatively low frequency of ETV6 homologue loss in ETV6/RUNX1-positive cases were distinct findings in this series. Additional genetic changes, such as ETV6 loss, extra RUNX1, ETV6/RUNX1 duplication, and MLL aberrations in the ETV6/RUNX1-positive group, supported the hypothesis of the ETV6/RUNX1 leukemogenic model that these secondary changes are necessary for leukemogenesis rather than progression of disease. This study disclosed RUNX1 alterations in the ETV6/RUNX1-negative group of BCP-ALL that encourages the investigation of RUNX1 at a large scale with longer follow-up, which will focus on the prognostic importance and the underlying biology of disease.     

RUNX1 aberrations in ETV6/RUNX1-positive and ETV6/RUNX1-negative patients: its hemato-pathological and prognostic significance in a large cohort (619 cases) of ALL

A large-cohort study (619) of acute lymphoblastic leukemia (ALL) revealed an ETV6/RUNX1 (previously known as TEL/AML1) incidence of 18% in pediatric B-cell precussor ALL, indicating no geographical heterogeinity. Association of CD34-negative phenotype, peak incidence in the 3- to 7-year age group, and a comparatively low frequency of ETV6 homologue loss in ETV6/RUNX1-positive cases were distinct findings in this series. Additional genetic changes, such as ETV6 loss, extra RUNX1, ETV6/RUNX1 duplication, and MLL aberrations in the ETV6/RUNX1-positive group, supported the hypothesis of the ETV6/RUNX1 leukemogenic model that these secondary changes are necessary for leukemogenesis rather than progression of disease. This study disclosed RUNX1 alterations in the ETV6/RUNX1-negative group of BCP-ALL that encourages the investigation of RUNX1 at a large scale with longer follow-up, which will focus on the prognostic importance and the underlying biology of disease.     

Loss at 12p detected by comparative genomic hybridization (CGH): association with TEL-AML1 fusion and favorable prognostic features in childhood acute lymphoblastic leukemia (ALL). A multi-institutional study.

BACKGROUND: Genetic aberrations provide prognostic information in childhood ALL. The proportion of patients with detectable aberrations can be increased by combining G-banding with comparative genomic hybridization (CGH). PROCEDURE: We studied 79 children with ALL by CGH and G-banding, and explored the relationship of these findings to clinical features and outcome. RESULTS: CGH revealed DNA copy number changes in 57 patients (72%), 9 of whom had normal karyotype by G-banding. Gains were more frequent than losses, and changes of whole chromosomes more frequent than partial aberrations. Two frequent partial losses were found; at 9p and 12p. The 9 patients with loss at 12p were studied for the deletion of TEL (ETV6) gene and the fusion of TEL and AML1 genes by fluorescent in situ hybridization (FISH). Eight out of the 9 children with loss at 12p harbored the TEL-AML1 translocation and all 9 had the deletion of a nontranslocated TEL allele. All 9 had precursor-B phenotype and L1 morphology, and 8/9 had WBC below 50 x 10(9)/liter. All children were treated according to Nordic ALL protocols, had a good response to treatment based on day 15 bone marrow morphology, and 7 out of the 9 survived in continuous complete remission (median follow-up 74 months). CONCLUSIONS: CGH is a valuable tool in screening for genetic aberrations in childhood ALL. DNA copy number losses detected at 12p associate with TEL-AML1 fusion as well as with favorable prognostic features.     

Acquired X-chromosome aneuploidy in children with acute lymphoblastic leukemia

BACKGROUND: A cytogenetic study of 75 consecutive children with ALL revealed a normal karyotype, a low hyperdiploid karyotype (including 47-50 chromosomes), and a high hyperdiploid karyotype (including > 50 chromosomes) in 10, 12, and 33 patients, respectively. An acquired extra X-chromosome was detected at diagnosis by conventional cytogenetics in 29 (88%) of 33 children with a high hyperdiploid karyotype and in 4 (33%) of 12 children with a low hyperdiploid karyotype. X-chromosome aneuploidy was retrospectively studied by fluorescence in situ hybridization (FISH) in eight and 20 patients with a normal and a hyperdiploid karyotype, respectively. PROCEDURE: A classical cytogenetic study was performed according to standard methods. FISH with the centromeric probe specific to X-chromosome was used to study interphase cells of bone marrow or blood samples. RESULTS: An extra X-chromosome was found by FISH in all 13 patients with a high hyperdiploid or tetraploid, in 6 of 7 patients with a low hyperdiploid, and in none with a normal karyotype. Two children with a normal karyotype displayed monosomy X. Altogether, 57.3% of newly diagnosed children displayed X-chromosome aneuploidy. CONCLUSIONS: Out study indicates that X-chromosome aneuploidy may be the most common chromosome abnormality in childhood ALL. It can be detected in nearly all children with a high hyperdiploid karyotype and up to one-half of the patients with a low hyperdiploid karyotype. FISH with an X-chromosome centromeric probe is a rapid and simple tool to detect an abnormal clone at diagnosis in the majority of children with ALL and is useful in confirming remission in these patients.     

Confirmation of chromosomal microarray as a first-tier clinical diagnostic test for individuals with developmental delay,intellectual disability,autism spectrum disorders and dysmorphic features

Background and objectivesSubmicroscopic chromosomal rearrangements are the most common identifiable causes of intellectual disability and autism spectrum disorders associated with dysmorphic features. Chromosomal microarray (CMA) can detect copy number variants <1 Mb and identifies size and presence of known genes. The aim of this study was to demonstrate the usefulness of CMA, as a first-tier tool in detecting the etiology of unexplained intellectual disability/autism spectrum disorders (ID/ASDs) associated with dysmorphic features in a large cohort of pediatric patients.Patients and methodsWe studied 349 individuals; 223 males, 126 females, aged 5 months-19 years. Blood samples were analyzed with CMA at a resolution ranging from 1 Mb to 40 Kb. The imbalance was confirmed by FISH or qPCR. We considered copy number variants (CNVs) causative if the variant was responsible for a known syndrome, encompassed gene/s of known function, occurred de novo or, if inherited, the parent was variably affected, and/or the involved gene/s had been reported in association with ID/ASDs in dedicated databases.Results91 CNVs were detected in 77 (22.06%) patients: 5 (6.49%) of those presenting with borderline cognitive impairment, 54 (70.13%) with a variable degree of DD/ID, and 18/77 (23.38%) with ID of variable degree and ASDs. 16/77 (20.8%) patients had two different rearrangements. Deletions exceeded duplications (58 versus 33); 45.05% (41/91) of the detected CNVs were de novo, 45.05% (41/91) inherited, and 9.9% (9/91) unknown. The CNVs caused the phenotype in 57/77 (74%) patients; 12/57 (21.05%) had ASDs/ID, and 45/57 (78.95%) had DD/ID.ConclusionsOur study provides further evidence of the high diagnostic yield of CMA for genetic testing in children with unexplained ID/ASDs who had dysmorphic features. We confirm the value of CMA as the first-tier tool in the assessment of those conditions in the pediatric setting.     

Clinical features and induction outcome of childhood acute lymphoblastic leukemia in a lower/middle income population: A multi‐institutional report from Pakistan

Background

Acute lymphoblastic leukemia (ALL) is the most common cancer of childhood. Some evidence suggests differences in clinical and cytogenetic characteristics of ALL based on geographic and ethnic variations. However, data on ALL characteristics and early outcome of therapy from low/middle‐income countries such as Pakistan are scanty.

Procedure

A prospective, multi‐institutional cohort study in Karachi enrolled 646 newly diagnosed children with ALL over 3 years. Standard forms were used to collect demographic, clinical, and laboratory data at presentation and at the end of induction.

Results

Of the total, 66.1% (n = 427) were males. Median age was 6 (mean ± SE 6.87 ± 0.16; range 0.16–18) years. The most common clinical presentation was fever (88.7%). BPC‐ALL was diagnosed in 78.5%, while 17.5% had T‐ALL; 28.8% had a WBC >50 × 10⁹/L. With 316 patients karyotyped, hypodiploidy and hyperdiploidy were seen in 5.1% and 10.7%, respectively. Of those tested, ETV6‐RUNX1 translocation was detected in 13.2%, while BCR‐ABL1 translocation and MLL gene rearrangements were seen in 7.3% and 4.6%, respectively. The cumulative loss to follow up before and during induction was 12.8% (n = 83) and 11.5% (n = 74) died before or during this phase. Induction was successfully completed by only 75.6% (n = 489) of the entire cohort and 69.6% (n = 450) achieved remission.

Conclusion

These patients had ALL with higher risk features than that reported from developed countries. One quarter failed to complete induction chemotherapy. This suboptimal result requires further study and development of innovative interventions, particularly focusing on the causes and solutions for late referral, abandonment, and infections. Pediatr Blood Cancer 2015;62:1700–1708. © 2015 Wiley Periodicals, Inc.