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9号染色体臂间倒位21例分析 Analyses in 21 Cases of Pericentric Inversion of Chromosome 9
李永全,郑克勤,周汝滨,潘超仁,廖霞,陈小萍LI Yong-quan,ZHENG Ke-qin,ZHOU Ru-bin,PAN Chao-ren,LIAO Xia,CHEN Xiao-ping
遗传 , 1999,
Abstract: 在2 703例遗传咨询门诊病例中检出9号染色体臂间倒位21例,将本组inv(9)的频率与普通群体inv(9)的频率作比较,并通过对伴有其它性状的inv(9)家系的分析,讨论了inv(9)的遗传效应问题。 Abstract: Twenty one cases of pericentric inversion of chromosome 9 were found in 2703 patients asking genetic counseling. The percentage of inv(9) in this group was compared with that in normal population. Two special pedigrees with inv(9) were analyzed and the genetic effects of inv(9) were discussed.
A Rare Case of Pericentric Inversion, Inv (21) (p12;q22) in Repeated Pregnancy Loss: A Case Report
Naeimeh Tayebi,Hossain Khodaei
Oman Medical Journal , 2011,
Abstract: Pericentric inversions are among the most frequent chromosomal rearrangements with a frequency of 1-2 20There is no phenotypic effect in the majority of pericentric inversion heterozygote carriers, when it is a balanced rearrangement. However, miscarriages, infertility and/or chromosomally unbalanced offspring can be observed in carriers of a pericentric inversion. This is a case of pericentric inversion of one chromosome 21: inv (21) (p12; q22) in repeated pregnancy loss. A couple was referred for cytogenetic examination due to idiopathic miscarriages. The proband proved to be a carrier of chromosomal inversion and her partner’s karyotype was found to be normal. The karyotype of the proband is 46, xx, inv (21) (p12; q22). This abnormal karyotype is reported as a probable reason of miscarriage in the investigated couple. The risk of further miscarriages and the risk of a progeny with abnormal karyotype are rather high. Therefore, amniocenthesis for finding the chromosomal abnormality as a prenatal diagnosis are proposed for the patient if future pregnancy does not lead to miscarriage.
The Kinetochore Is an Enhancer of Pericentric Cohesin Binding  [PDF]
Stewart A. Weber,Jennifer L. Gerton,Joan E. Polancic,Joseph L. DeRisi,Douglas Koshland,Paul C. Megee
PLOS Biology , 2012, DOI: 10.1371/journal.pbio.0020260
Abstract: The recruitment of cohesins to pericentric chromatin in some organisms appears to require heterochromatin associated with repetitive DNA. However, neocentromeres and budding yeast centromeres lack flanking repetitive DNA, indicating that cohesin recruitment occurs through an alternative pathway. Here, we demonstrate that all budding yeast chromosomes assemble cohesin domains that extend over 20–50 kb of unique pericentric sequences flanking the conserved 120-bp centromeric DNA. The assembly of these cohesin domains requires the presence of a functional kinetochore in every cell cycle. A similar enhancement of cohesin binding was also observed in regions flanking an ectopic centromere. At both endogenous and ectopic locations, the centromeric enhancer amplified the inherent levels of cohesin binding that are unique to each region. Thus, kinetochores are enhancers of cohesin association that act over tens of kilobases to assemble pericentric cohesin domains. These domains are larger than the pericentric regions stretched by microtubule attachments, and thus are likely to counter microtubule-dependent forces. Kinetochores mediate two essential segregation functions: chromosome movement through microtubule attachment and biorientation of sister chromatids through the recruitment of high levels of cohesin to pericentric regions. We suggest that the coordination of chromosome movement and biorientation makes the kinetochore an autonomous segregation unit.
The Kinetochore Is an Enhancer of Pericentric Cohesin Binding  [PDF]
Stewart A Weber,Jennifer L Gerton,Joan E Polancic,Joseph L DeRisi,Douglas Koshland,Paul C Megee
PLOS Biology , 2004, DOI: 10.1371/journal.pbio.0020260
Abstract: The recruitment of cohesins to pericentric chromatin in some organisms appears to require heterochromatin associated with repetitive DNA. However, neocentromeres and budding yeast centromeres lack flanking repetitive DNA, indicating that cohesin recruitment occurs through an alternative pathway. Here, we demonstrate that all budding yeast chromosomes assemble cohesin domains that extend over 20–50 kb of unique pericentric sequences flanking the conserved 120-bp centromeric DNA. The assembly of these cohesin domains requires the presence of a functional kinetochore in every cell cycle. A similar enhancement of cohesin binding was also observed in regions flanking an ectopic centromere. At both endogenous and ectopic locations, the centromeric enhancer amplified the inherent levels of cohesin binding that are unique to each region. Thus, kinetochores are enhancers of cohesin association that act over tens of kilobases to assemble pericentric cohesin domains. These domains are larger than the pericentric regions stretched by microtubule attachments, and thus are likely to counter microtubule-dependent forces. Kinetochores mediate two essential segregation functions: chromosome movement through microtubule attachment and biorientation of sister chromatids through the recruitment of high levels of cohesin to pericentric regions. We suggest that the coordination of chromosome movement and biorientation makes the kinetochore an autonomous segregation unit.
Trisomía 21. Reporte de dos Casos con Cariotipos poco usuales
Sánchez,Otto; de Marade,Sonia; Guerra,Dania;
Investigación Clínica , 2001,
Abstract: we report two patients with trisomy 21 whose cariotypes revealed unusual translocations. in the first case there was a tandem translocation with two chromosomes 21 attached to the long arm of chromosome 10 (45,xx + tan(10:21;21). in the second case there was an inverted tandem translocation between two chromosomes 21 attached through their long arms (46,xy+ dic(21q:21q). the clinical picture in both patients was not different from the usually found in trisomy 21. since the parent?s cariotypes were normal in both cases, it is assumed that both translocations arose "de novo". the need for cariotyping all cases of down syndrome is emphasized.
Cytogenetic Analysis of a Few Partial Trisomy 9p Coming from a Balanced Translocation between Chromosome 9 and 21
9; 21相互易位携带者生育多例9p部分三体患者细胞遗传学分析

WANG Xiao-Ran,LUO Rui-Li,DAI Xiao-Hua,LIU Jing-Yu,
王晓然
,罗瑞丽,代小华,刘静宇

遗传 , 2007,
Abstract: In this study, a four-generation Chinese family in Nanyang, Henan Province was identified with partial trisomy 9p syndrome. Of the 23 family members studied, six were characterized with mental retardation and mild facial and little finger anomalies. All affected family members demonstrated significant intrafamilial homogeneous phenotype except concomitance epilepsy in proband. On the basis of G-banding, the proband showed a translocation between chromosomes of 9p and 21q and partial 9p trisomy. The karyotype was 46, XY, der (21) t (9; 21) (9p22.2; 21q22.3) pat. Further karyotyping of other affected members and their patients in this family revealed translocation of chromosomes of 9p and 21q, with partial 9p trisomy in all affected members. The partial 9p trisomy was the direct result of abnormal segregation of a balanced translocation cell between chromosome 9 and 21 in one of the parents. The extra distal half of the short arm of chromosome, 9pter-->9p21, is responsible for the major clinical features such as mental retardation and mild facial anomaly. The cause of epilepsy in proband was discussed.
Trisomía 21. Reporte de dos Casos con Cariotipos poco usuales
Otto Sánchez,Sonia de Marade,Dania Guerra
Investigación Clínica , 2001,
Abstract: Se presentan dos pacientes con trisomía 21 en quienes el análisis cromosómico reveló translocaciones poco usuales. En el primer caso se trataba de una translocación en tandem donde dos cromosomas 21 estaban unidos al brazo largo del cromosoma 10 (45, XX + tan(10;21;21)). En el segundo caso se evidenció la presencia de una translocación entre dos cromosomas 21 unido a través de sus brazos largos en translocación tandem invertida (46,XY + dic(21q:21q)). El cuadro clínico de ambos pacientes no difería de los hallazgos usuales en esta enfermedad. En ambos casos el cariotipo de los progenitores era normal por lo que se asume que las anomalías cromosómicas fueron eventos "de novo". Se enfatiza la necesidad de realizar cariotipo en todo paciente con Síndrome de Down. We report two patients with trisomy 21 whose cariotypes revealed unusual translocations. In the first case there was a tandem translocation with two chromosomes 21 attached to the long arm of chromosome 10 (45,XX + tan(10:21;21). In the second case there was an inverted tandem translocation between two chromosomes 21 attached through their long arms (46,XY+ dic(21q:21q). The clinical picture in both patients was not different from the usually found in trisomy 21. Since the parent’s cariotypes were normal in both cases, it is assumed that both translocations arose "de novo". The need for cariotyping all cases of Down syndrome is emphasized.
Focal cortical dysplasia and pericentric inversion of chromosome 9: a case report
Giancarlo DI GENNARO,Addolorata MASCIA,Liliana G. GRAMMALDO,Fabio SEBASTIANO
Journal of Neurological Sciences , 2004,
Abstract: A child affected by multiple dysmorphisms and behavioral disorders with pericentric inversion on chromosome 9 [46 XY inv 9 (p11q11)] is reported. In this patient, a focal cortical dysplasia in right temporal lobe was observed on magnetic resonance imaging of the brain. To our knowledge, this report is the first description of focal cortical dysplasia in a patient of an occidental country with pericentric inversion of chromosome. 9. The relationship between alterations localised on chromosome 9 and cerebral cortical organisation disorders is discussed.
The Proper Splicing of RNAi Factors Is Critical for Pericentric Heterochromatin Assembly in Fission Yeast  [PDF]
Scott P. Kallgren,Stuart Andrews equal contributor,Xavier Tadeo equal contributor,Haitong Hou equal contributor,James J. Moresco,Patricia G. Tu,John R. Yates III,Peter L. Nagy,Songtao Jia
PLOS Genetics , 2014, DOI: doi/10.1371/journal.pgen.1004334
Abstract: Heterochromatin preferentially assembles at repetitive DNA elements, playing roles in transcriptional silencing, recombination suppression, and chromosome segregation. The RNAi machinery is required for heterochromatin assembly in a diverse range of organisms. In fission yeast, RNA splicing factors are also required for pericentric heterochromatin assembly, and a prevailing model is that splicing factors provide a platform for siRNA generation independently of their splicing activity. Here, by screening the fission yeast deletion library, we discovered four novel splicing factors that are required for pericentric heterochromatin assembly. Sequencing total cellular RNAs from the strongest of these mutants, cwf14Δ, showed intron retention in mRNAs of several RNAi factors. Moreover, introducing cDNA versions of RNAi factors significantly restored pericentric heterochromatin in splicing mutants. We also found that mutations of splicing factors resulted in defective telomeric heterochromatin assembly and mis-splicing the mRNA of shelterin component Tpz1, and that replacement of tpz1+ with its cDNA partially rescued heterochromatin defects at telomeres in splicing mutants. Thus, proper splicing of RNAi and shelterin factors contributes to heterochromatin assembly at pericentric regions and telomeres.
Homozygosity for Pericentric Inversions of Chromosome 9 in a Patient’s Parents with Stillbirth- Report of a New Case and Review of Literature
M Khaleghian,C Azimi
Iranian Journal of Public Health , 2006,
Abstract: Pericentric inversions of chromosome 9 are among the most frequent chromosomal rearrangement in human. A few cytogeneticists consider inversions of chromosome 9 as a normal variant. However, many reports in the recent literature link pericentric inversions of chromosome 9 with infertility, recurrent abortions, and a number of other abnormal conditions. We report a case of homozygosity pericentric inversions of chromosome 9 in a woman with 28- wk stillbirth. In this case, her both parents were heterozygotes for the inversions of chromosome 9.
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