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31.
A large family with an inherited reciprocal translocation (16;21) is described. An unbalanced karyotype due to adjacent-1 segregation was documented in 6 cases, whereas 25 children dying within the first year of life and 4 individuals dying at later ages probably had the same abnormality. Therefore minimal and maximal risk estimates were calculated to be 6.0% and 26.5% for female, respectively, 4.8% and 33.3% for male translocation heterozygotes. Among the karyotyped phenotypically normal offspring of male as well as female carriers the ratio of normal children to balanced carriers was not different from 1:1. 相似文献
32.
Lura Brianna Caddle Jeremy L. Grant Jin Szatkiewicz Johann van Hase Bobbi-Jo Shirley Joerg Bewersdorf Christoph Cremer Alain Arneodo Andre Khalil Kevin D. Mills 《Chromosome research》2007,15(8):1061-1073
Radiation exposure is an occupational hazard for military personnel, some health care professionals, airport security screeners,
and medical patients, with some individuals at risk for acute, high-dose exposures. Therefore, the biological effects of radiation,
especially the potential for chromosome damage, are major occupational and health concerns. However, the biophysical mechanisms
of chromosome instability subsequent to radiation-induced DNA damage are poorly understood. It is clear that interphase chromosomes
occupy discrete structural and functional subnuclear domains, termed chromosome territories (CT), which may be organized into
‘neighborhoods’ comprising groups of specific CTs. We directly evaluated the relationship between chromosome positioning,
neighborhood composition, and translocation partner choice in primary lymphocytes, using a cell-based system in which we could
induce multiple, concentrated DNA breaks via high-dose irradiation. We critically evaluated mis-rejoining profiles and tested
whether breaks occurring nearby were more likely to fuse than breaks occurring at a distance. We show that CT neighborhoods
comprise heterologous chromosomes, within which inter-CT distances directly relate to translocation partner choice. These
findings demonstrate that interphase chromosome arrangement is a principal factor in genomic instability outcomes in primary
lymphocytes, providing a structural context for understanding the biological effects of radiation exposure, and the molecular
etiology of tumor-specific translocation patterns. 相似文献
33.
目的 探讨一例核型为47,XY,t(5;17),+22的少见急性早幼粒细胞白血病(acute promyelo-cytic leukemia,APL)的临床和实验特征.方法 在常规核型分析的基础上,应用荧光原位杂交(fluorescencein situ hybridization,FISH)和多重荧光原位杂交(multiplex fluorescence in situ hybridization,M-FISH)技术进一步检测该病例的细胞遗传学异常,并结合文献分析此类少见变异易位的临床特点.结果 FISH检测PML-RARa阴性,但77%的细胞显示存在17号RARa基因的重排或复制;BCR-ABL阴性,但74%的细胞显示有22号染色体的复制或重排.M-FISH明确RARa基因重排系5号与17号染色体易位所致,并证实了22号三体的存在.结论 变异型t(5;17)易位,形成NPM-RARa融合基因的急性早幼粒细胞白血病是APL中少见的类型.骨髓形态表现为奥氏小体缺如,核型中常伴有其它附加染色体异常,全反式维甲酸(all-trans retinoicacid,ATRA)联合化疗有效,但易复发,合并弥漫性血管内凝血及高白细胞者预后凶险. 相似文献
34.
The patient presented with the typical features of Down syndrome: hypotonia, brachycephaly, flattened occiput, bilateral prominent medical epican-thic folds, flat nasal bridge, protruding tongue, low-set dysplastic ears, short broad hands, bilateral clinodactyly and simian crease. The karyotype of this child was originally reported as normal. High-resolution chromosomes revealed extra material on the long arm of chromosome 18. The mother's karyotype showed a reciprocal translocation between the long arm of 18 and the long arm of 21 at band q23 and q22.1, respectively. FISH performed separately with two different 21q cosmid probes gave two signals on the mother's metaphases and three signals on the prob-and. These findings confirmed that the proband is trisomic for the long arm of chromosome 21 at loci D21S65 and D21S19. 相似文献
35.
Familial partial trisomy 5p resulting from segregation of an insertional translocation 总被引:1,自引:0,他引:1
A case of duplication of segment p13-p15 of the short arm of chromosome 5 as the result of an insertional translocation in a mentally retarded girl with congenital anomalies is reported. Some of the apparently balanced carriers of the inverted insertion showed minor congenital anomalies. 相似文献
36.
J. L. Deuve N. C. Bennett P. C. M. O’Brien M. A. Ferguson-Smith C. G. Faulkes J. Britton-Davidian T. J. Robinson 《Chromosome research》2006,14(6):681-691
Cross-species chromosome painting was used to determine homologous chromosomal regions between two species of mole-rat, the
naked mole-rat, Heterocephalus glaber (2n = 60), and the giant mole-rat, Cryptomys mechowi (2n = 40), using flow-sorted painting probes representative of all but two of the H. glaber chromosomal complement. In total 43 homologous regions were identified in the C. mechowi genome. Eight H. glaber chromosomes are retained in toto in C. mechowi, and 13 produce two or more signals in this species. The most striking difference in the karyotypes of the two taxa concerns
their sex chromosomes. The H. glaber painting probes identified a complex series of translocations that involved the fractionation of four autosomes and the subsequent
translocation of segments to the sex chromosomes and to autosomal partners in the C. mechowi genome. An intercalary heterochromatic block (IHB) was detected in sex chromosomes of C. mechowi at the boundary with the translocated autosomal segment. We discuss the likely sequence of evolutionary events that has led
to the contemporary composition of the C. mechowi sex chromosomes, and consider these in the light of prevailing views on the genesis of sex chromosomes in mammals. 相似文献
37.
目的运用全染色体探针荧光原位杂交技术(fluorescent in situ hybridization ,FISH)对14/21罗伯逊易位携带者的胚胎进行植入前遗传学诊断,达到优生目的.方法应用FITC、Texas标记的21/14全染色体探针对14/21罗伯逊易位携带者的胚胎活检后的单个卵裂球进行遗传学检测,选择正常信号或携带者信号核型胚胎进行移植.结果常规单精子显微注射-胚胎移植(intracytoplasmic sperm injection,ICSI)后获取胚胎12个,活检优质胚胎11个,杂交后有信号胚胎7个,其中1个正常胚胎,1个携带者胚胎;1个14单体胚胎,1个21单体胚胎,1个21三体胚胎,另2个胚胎活检后均为21号二体,无14号信号.结论运用14/21全染色体探针荧光原位杂交技术对14/21罗伯逊易位携带者的胚胎进行植入前遗传学诊断是能够将正常核型胚胎挑选出来进行移植,从而达到优生目的. 相似文献
38.
Trisomy 17p due to a t(8; 17) (p23; p11.2)pat translocation. Case report and review of the literature 总被引:2,自引:0,他引:2
We describe a female newborn girl with partial trisomy 17p, which was not detected at the initial cytogenetic investigation, but which later proved to be an unbalanced product of a paternal translocation t(8; 17)(p23;pl 1.2). Comparison with the three previously reported patients suggests a clinically distinct "trisomy 17p syndrome", i.e. pre- and postnatal growth retardation, microcephaly, antimongoloid slanting of palpebral fissures, hypertelorism, long philtrum with thin upper lip, micrognathia and high-arched palate. Two of the four patients had a heart defect, and psychomotor developmental delay was evident in all four cases. In the present patient, the chromosomal anomaly was only detected after the finding of the autosomal reciprocal translocation in the father. The importance of cytogenetic investigations in parents of a MCA/MR child with apparently normal chromosomes is emphasized. 相似文献
39.
Telomere-specific fluorescence in situ hybridization analysis of couples with five or more recurrent miscarriages 总被引:1,自引:0,他引:1
Fluorescence in situ hybridization analysis using telomere specific probes has been used to detect cryptic translocations in the chromosomal telomeric regions. This study was performed in five clinically normal couples who have had five or more spontaneous abortions and whose karyotypes were found to be normal using conventional cytogenetic techniques. Using the telomere specific probes, in one couple we determined a cryptic translocation between chromosome 3 and 10, and, in another couple, the signal in chromosome 20 was detected in another chromosome, which was probably a D group chromosome. Additionally, in the latter and also in two other couples, we observed a polymorphism. The approach will be helpful for screening cryptic translocations using telomere specific multiple probe sets in couples with recurrent miscarriages. As prenatal diagnosis will be available for these couples for future pregnancies, it will be possible to help these families to have healthy fetuses. 相似文献
40.
Eiko Arai Shuichi Nishimura Kenichi Tamura Mitsushiro Kida Tatsuro Ikeuchi 《Journal of human genetics》1994,39(4):433-437
Summary Distal deletion of chromosome 1q has been reported in nearly 30 patients, all being associated with a deletion ranging from the 1q42 or q43 band to 1qter region. Here, we describe a girl with 1q terminal deletion resulting from an unbalancedde novo translocation t(1;D or G)(q44; p11), as revealed by the presence of a satellited feature and an NOR-stained region at the tip of 1q. We suggest that most of the phenotypic abnormalities seen in patients with 1q distal deletion are attributable to the monosomy for band 1q44. 相似文献