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  2. Barr body - Wikipedia

    en.wikipedia.org/wiki/Barr_body

    Barr bodies can be seen in neutrophils at the rim of the nucleus. In humans with more than one X chromosome, the number of Barr bodies visible at interphase is always one fewer than the total number of X chromosomes. For example, people with Klinefelter syndrome (47, XXY) have a single Barr body, and people with a 47, XXX karyotype have two ...

  3. Sex-chromosome dosage compensation - Wikipedia

    en.wikipedia.org/wiki/Sex-chromosome_dosage...

    Replicating the actual gene is impossible; thus organisms instead equalize the expression from each gene. For example, in humans, female (XX) cells randomly silence the transcription of one X chromosome, and transcribe all information from the other, expressed X chromosome. Thus, human females have the same number of expressed X-linked genes ...

  4. XX male syndrome - Wikipedia

    en.wikipedia.org/wiki/XX_male_syndrome

    [28] [23] Another proposed cause is mutations to the DAX1 gene, which may suppress masculinisation; if there is a loss of function of DAX1, then testes can develop in an XX individual. [ 29 ] [ 30 ] Mutations in SF1 and WNT4 genes have also been studied in connection with SRY-negative 46 XX female XX male syndrome .

  5. X-inactivation - Wikipedia

    en.wikipedia.org/wiki/X-inactivation

    The Xist gene is expressed at high levels on the Xi and is not expressed on the Xa. [39] Many other genes escape inactivation; some are expressed equally from the Xa and Xi, and others, while expressed from both chromosomes, are still predominantly expressed from the Xa. [40] [41] [42] Up to one quarter of genes on the human Xi are capable of ...

  6. Klinefelter syndrome - Wikipedia

    en.wikipedia.org/wiki/Klinefelter_syndrome

    In the past, the observation of the Barr body was common practice, as well. [47] To investigate the presence of a possible mosaicism, analysis of the karyotype using cells from the oral mucosa is performed. Physical characteristics of a Klinefelter syndrome can be tall stature, low body hair, and occasionally an enlargement of the breast.

  7. XXYY syndrome - Wikipedia

    en.wikipedia.org/wiki/XXYY_syndrome

    48,XXYY syndrome is a condition related to the X and Y chromosomes (the sex chromosomes). People normally have 46 chromosomes in each cell.Two of the 46 chromosomes, known as X and Y, are called sex chromosomes because they help determine whether a person will develop male or female sex characteristics.

  8. X-chromosome reactivation - Wikipedia

    en.wikipedia.org/wiki/X-chromosome_reactivation

    X chromosome reactivation (XCR) is the process by which the inactive X chromosome (the Xi) is re-activated in the cells of eutherian female mammals. Therian female mammalian cells have two X chromosomes, while males have only one, requiring X-chromosome inactivation (XCI) for sex-chromosome dosage compensation.

  9. The genes most often mutated are GAK (25.9% of cases), beta-catenin (22.9%), TP53 (22.7%), and ECSIT (19.3%). These genes regulate cell growth and survival. [16] Other genes (e.g. JAK3, STAT3, and STAT5B) that are mutated in far lower percentages of cases also regulate these potentially pro-malignant cell functions. However, the relationship of ...