The behavior of sex chromosomes in two human X-autosome translocations: failure of extensive X-inactivation spreading
Biocell
; Biocell;25(2): 155-166, Aug. 2001.
Article
em En
| LILACS
| ID: lil-335878
Biblioteca responsável:
BR1.1
RESUMO
Two patients, one adult male and one infant girl, bearing different X-autosome translocations, were studied with cytogenetical, ultrastructural and chromosome-painting techniques. The adult male, is a carrier of a reciprocal, balanced translocation involving the X and #2 chromosomes 46,Y,t(X;2) (q13;p21). This man showed infertility with spermatogenesis arrest at the spermatocyte stage. Synaptonemal complex analysis at pachytene showed the quadrivalent structure and the putative breakage points. Sex-chromatin condensation did not spread towards the autosomal regions of the quadrivalent. The female infant showed diminished body growth and multiple somatic anomalies. She is a 45,Xp-,t(X;21)(p11;p13) carrier, an unbalanced translocation involving chromosomes X and #21, which leads to a monosomy of almost all Xp. The translocated #21 is practically complete, and its centromere is the active one in the rearranged product. The analysis of interphase nuclei with the X-centromere probe shows that the Xq region of the rearranged chromosome is the late -replicating and inactive element. However, X-inactivation does not spread to the attached #21, as shown by the R-banding pattern. Thus, both in the male adult and in the female infant there is a barrier to the spreading effect of X-chromosome inactivation, which is probably due to different mechanisms.
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Coleções:
01-internacional
Base de dados:
LILACS
Assunto principal:
Translocação Genética
/
Cromossomo X
/
Cromossomos Humanos Par 21
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Mecanismo Genético de Compensação de Dose
Limite:
Adult
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Child, preschool
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Female
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Humans
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Male
Idioma:
En
Revista:
Biocell
Assunto da revista:
Clulas
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Argentina