45，X/46，X，+mar男性患儿临床及遗传学分析

目的分析45,X/46,X,+mar男性患儿的临床及遗传学特征。方法回顾分析2例确诊45,X/46,X,+mar男性患儿的临床资料,并复习相关文献。结果2例男性患儿,年龄分别为10岁7个月和3岁1个月,均有矮小表现,且伴有性腺发育落后。例1合并精索静脉曲张,头颅磁共振成像示部分空蝶鞍,外周血染色体核型分析为45,X[31]/46,X,+mar[69],二代测序检测提示Y染色体短臂SRY基因拷贝数重复,长臂USP9Y基因整体缺失。例2外周血染色体核型分析也为45,X[5]/46,X,+mar[75],全基因组CNV检测提示染色体核型为46,XY,Y染色体AZFb+AZFc区域完全缺失。结论矮小症患儿应密切关注其外生殖器的形态及功能,必要时进行遗传学分析。     

Acute myeloid leukemia with inv(3)(q21q26.2) or t(3;3)(q21;q26.2): Clinical and biological features and comparison with other acute myeloid leukemias with cytogenetic aberrations involving long arm of chromosome 3

Abstract

Objectives: To compare, from a biological and clinical perspective, a significant group of patients with AML with inv(3)(q21q26.2) or t(3;3)(q21;q26.2) with another group of AML carrying different abnormalities of 3q at q21 or q26, the latter named as the AML abn(3q) group. Methods: We developed a national survey with the participation of 13 Spanish hospitals, and retrospectively reviewed (from 1990 to 2010) these subtypes of AML. Fifty-five patients were collected: 35 with AML inv(3)/t(3;3) and 20 with AML abn(3q). A data collecting page that included main features at diagnosis, therapeutic approach and response, and survival variables, was distributed and completed. Results: We did not find significant differences in sex, age, history of myelodysplastic syndrome or chemo-/radiotherapy, clinical presentation, WBC and platelet counts, hemoglobin level, blasts immunophenotype, serum lactatedehydrogenase, peripheral blood and bone marrow cellular dysplasia, and bone marrow biopsy findings. Although the association with monosomy 7 was significantly more frequent in AML inv(3)/t(3;3), this did not seem to influence outcome. The lack of response to the different modalities of treatment and the aggressive course of the disease were the standard in both cohorts of patients. Discussion: Although not yet recognized by the World Health Organization classification, our results are in agreement with the findings of other authors, who include both subsets of AML together in the same group of adverse prognosis. Conclusion: In an attempt to simplify and bound entities with similar genetic background and clinical behavior, it would be desirable to bring together both subgroups of AML in a single section.     

Differential effect of aneuploidy on the X chromosome and genes with sex-biased expression in Drosophila

Global analysis of gene expression via RNA sequencing was conducted for trisomics for the left arm of chromosome 2 (2L) and compared with the normal genotype. The predominant response of genes on 2L was dosage compensation in that similar expression occurred in the trisomic compared with the diploid control. However, the male and female trisomic/normal expression ratio distributions for 2L genes differed in that females also showed a strong peak of genes with increased expression and males showed a peak of reduced expression relative to the opposite sex. For genes in other autosomal regions, the predominant response to trisomy was reduced expression to the inverse of the altered chromosomal dosage (2/3), but a minor peak of increased expression in females and further reduced expression in males were also found, illustrating a sexual dimorphism for the response to aneuploidy. Moreover, genes with sex-biased expression as revealed by comparing amounts in normal males and females showed responses of greater magnitude to trisomy 2L, suggesting that the genes involved in dosage-sensitive aneuploid effects also influence sex-biased expression. Each autosomal chromosome arm responded to 2L trisomy similarly, but the ratio distributions for X-linked genes were distinct in both sexes, illustrating an X chromosome-specific response to aneuploidy.Changes in chromosomal dosage have long been known to affect the phenotype or viability of an organism (1–4). Altering the dosage of individual chromosomes typically has a greater impact than varying the whole genome (5–7). This general rule led to the concept of “genomic balance” in that dosage changes of part of the genome produce a nonoptimal relationship of gene products. The interpretation afforded these observations was that genes on the aneuploid chromosome produce a dosage effect for the amount of gene product present in the cell (8).However, when gene expression studies were conducted on aneuploids, it became known that transacting modulations of gene product amounts were also more prevalent with aneuploidy than with whole-genome changes (9–14). Assays of enzyme activities, protein, and RNA levels revealed that any one chromosomal segment could modulate in trans the expression of genes throughout the genome (9–15). These modulations could be positively or negatively correlated with the changed chromosomal segment dosage, but inverse correlations were the most common (10–13). For genes on the varied segment, not only were dosage effects observed, but dosage compensation was also observed, which results from a cancelation of gene dosage effects by inverse effects operating simultaneously on the varied genes (9, 10, 14–18). This circumstance results in “autosomal” dosage compensation (14, 16–18). Studies of trisomic X chromosomes examining selected endogenous genes or global RNA sequencing (RNA-seq) studies illustrate that the inverse effect can also account for sex chromosome dosage compensation in Drosophila (15, 19–21). In concert, autosomal genes are largely inversely affected by trisomy of the X chromosome (15, 19, 21).The dosage effects of aneuploidy can be reduced to the action of single genes whose functions tend to be involved in heterogeneous aspects of gene regulation but which have in common membership in macromolecular complexes (8, 22–24). This fact led to the hypothesis that genomic imbalance effects result from the altered stoichiometry of subunits that affects the function of the whole and that occurs from partial but not whole-genome dosage change (8, 22–25). Genomic balance also affects the evolutionary trajectory of duplicate genes differently based on whether the mode of duplication is partial or whole-genome (22, 23).Here we used RNA-seq to examine global patterns of gene expression in male and female larvae trisomic for the left arm of chromosome 2 (2L). The results demonstrate the strong prevalence of aneuploidy dosage compensation and of transacting inverse effects. Furthermore, because both trisomic males and females could be examined, a sexual dimorphism of the aneuploid response was discovered. Also, the response of the X chromosome to trisomy 2L was found to be distinct from that of the autosomes, illustrating an X chromosome-specific effect. Genes with sex-biased expression, as determined by comparing normal males and females, responded more strongly to trisomy 2L. Collectively, the results illustrate the prevalence of the inverse dosage effect in trisomic Drosophila and suggest that the X chromosome has evolved a distinct response to genomic imbalance as would be expected under the hypothesis that X chromosome dosage compensation uses the inverse dosage effect as part of its mechanism (15).     

Severe hemorrhagic colitis in a patient with chronic myeloid leukemia in the blastic phase after dasatinib use

Dasatinib is a second-line tyrosine kinase inhibitor used in patients with imatinib resistant or intolerant chronic myeloid leukemia (CML) and Philadelphia chromosomepositive acute leukemia. Gastrointestinal bleeding may occur in up to 7% of patients using dasatinib, although, severe dasatinib-related acute colitis had rarely been reported. Here, we present the case of a 36-year-old female who progressed to acute myeloid leukemia after fourteen months of receiving imatinib for CML in the chronic phase and was treated with a dasatinib-containing chemotherapy regimen. On day 34 of treatment, the patient developed moderate abdominal pain and bloody diarrhea with mucous. Analyses of stool specimens were negative for parasites, Clostridium difficile , and other pathogenic bacteria. The cytomegalovirus pp65 antigen was negative in her blood leukocytes. A colonoscopy revealed acute colitis, and a mucosal biopsy showed nonspecific colitis. The patient was treated with broad-spectrum antibiotics, bowel rest and hydration, and dasatinib treatment was stopped. Her bloody diarrhea improved within 72 h. After confirming cytological remission, the patient received initial course of consolidation, and dasatinib treatment was reinstated. However, hemorrhagic colitis recurred. After discontinuing dasatinib, herhemorrhagic colitis drastically improved and did not recur following the administration of nilotinib. The characteristics of our patient suggest that dasatinib treatment can lead to hemorrhagic colitis, which typically resolves after discontinuation of the drug.     

严重生精功能障碍患者助孕前遗传学检查的意义

检测严重生精功能障碍患者外周血染色体，为拟行ICSI技术助孕的患者提供遗传咨询。方法按常规方法进行外周血淋巴细胞培养、染色体制备、核型分析。结果61例无精子症患者中有22例染色体核型异常，异常率36.1%：36例严重少精子症患者中有1例染色体异常，异常率2.78%，根据染色体结果及生精功能障碍程度选择不同的诊治方案。结诊（1）染色体异常是导致男性生精功能障碍的重要原因之一。（2）ICSI助孕前，夫妇双方须行遗行学检查以避免遗传缺陷后代的出生。     

低剂量辐射诱导细胞遗传学适应性反应的某些规律

10mGyX射线可诱导人外周血淋巴细胞和家兔外周血淋巴细胞产生对相继较大剂量(1.5Gy)X射线诱发染色体畸变的抗性, 称之为适应性反应。在离体和整体条件下, 该反应广泛存在于体细胞和生殖细胞中, 其反应程度与低剂量辐射的剂量呈负相关, 即辑先照射的剂量愈低, 诱导的适应性反应愈明显。同时还发现该反应也受许多因素的影响, 如: 低剂量辐射的剂量、剂量率, 照射时间以及生物个体差异等因素。     

男性不育患者Y染色体微缺失的多重PCR筛查

【目的】建立一套Y染色体微缺失的多重PCR筛查方法 ,对因无精症或少精症欲行单精子卵细胞浆注射 (ICSI)治疗的男性不育患者进行Y染色体微缺失的常规筛查。【方法】建立两套稳定和可靠的五重PCR筛查方法 ,对在本中心进行ICSI治疗的 2 6例无精症患者和 6 1例少精症患者进行Y染色体微缺失的检测。【结果】在 2 6例无精症患者中发现 1例有Y染色体AZFc/DAZ的缺失 ,在 6 1例少精症患者中发现 4例Y染色体AZFc/DAZ的缺失。【结论】本研究Y染色体微缺失的多重PCR筛查方法是易行和可靠的。     

Identification of the chromosome 14 origin of a C-negative marker associated with a 14q32 deletion by chromosome painting

A constitutional chromosome 14 rearrangement was observed in a female with a psychodevelopmental disorder. Karyotype analysis using a variety of chromosome techniques, QFQ, GTG, CBG, Ag-NOR and DA-DAPI, showed a deletion of chromosome 14q32.1-qter region in association with a supernumerary marker chromosome. The marker, resembling a submetacentric, approximately half the size of a G group chromosome is C band and Ag-NOR negative. The heteromorphism of the satellites showed that the deleted chromosome 14 is paternal in origin. Chromosome painting using an Alu-PCR probe specific for the human chromosome 14 and fluorescent in situ hybridization (FISH) showed that the marker contains chromosome 14q32 sequences. It is likely that the marker was generated from the deleted chromosome 14 region through a complex rearrangement.     

识别正常人类G带染色体的标准与鉴别检索表——Ⅱ.Prometaphase haploid 500带期

<正> 4.染色体最大。P上有9个深色带.其中第1带(P21)最宽,其次为第3带(P31.1),其余带均窄。P端部为浅色带。q远端的4个带的宽窄大小由近至远的顺序为窄宽窄宽(即q32.2q42.2相似文献