Klinefelter syndrome is caused by an extra X chromosome in males (XXY), leading to specific physical characteristics due to abnormal chromosome composition.
Klinefelter syndrome is caused by an extra X chromosome present in the cells of a male, resulting in a genotype of XXY. This syndrome leads to male individuals with characteristics such as small testes, enlarged breasts, and reduced body hair due to the inhibitory effect of the additional X chromosome on male development. In Klinefelter syndrome, every X chromosome, except one, undergoes inactivation to compensate for the excess genetic dosage (Barr bodies).
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