Question

What is the difference between a woman with 45, X and one with 46, XX given that in all of the cells of a 46, XX individual one X chromosome is inactivated anyway?

Girls with Turner's syndrome are a little shorter than average, have a thicker neck, usually can't have children and can be socially inept - they butt into conversations, misread body language, are insensitive to others' feelings… In essence they act a lot like boys. Why might this be? (Hint: where do boys get their X chromosome?)

Using the parental Meiotic Nondisjunction rates from the class powerpoint make an argument about the % of Turner’s individuals that are socially inept versus socially competent.

Answer 1

• X-inactivation seen in a woman with 46, XX , out of the two XX, one X is inactivated in all the cells.
• In the persons with 46, XX , out of the two XX, if X is inactivated some of the cells with X inherited from mother becomes inactivated and some of the cells with X inherited from father becomes inactivated.
• Whatever the cell gets inactivated, through mitosis it produces, the daughter cells which all inactivated.
• Monosomy could be seen in Turner’s syndrome, with one X as seen in woman with 45, X.
• Because of X-inactivation, females like males also have a single X-chromosome in somatic cells. This leads to male stature in females.
• also show a single X-chromosome like in males but lot of deleterious effects could be seen due to X-inactivation in females,
• When pseudoautosomal genes which generally get matched in both x and Y chromosomes and generally they pass like autosomes to next generation.
• If the pseudoautosomal genes have inactivated during X-inactivation of one of the x chromosome, thereby it leads to see more male characters due to dosage compensation in females suffering with turners syndrome.