Xxy males

... However, one can be born with extra chromosome(s), e.g. they can have XXY, XYY, XXXY, XXX or some other such genotype. These cause different syndromes depending on the combination. For example, XYY males are generally healthy, though have an increased risk of learning difficulties ...

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X chromosome inactivation also occurs in males, in Klinefelter syndrome (XXY), but what happens if the individual has an extra Y chromosome (XYY)? Does one Y chromosome inactivate?

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if you have XXY you have kleinfelters.... (and if you have XXXY you still have kleinfelters) down syndrome ... and trisomy 21 are a consequence of non-disjunction. There are many examples of males born with XYY and XYYY... in the past, they even tried to link this karyotype with ...

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