This thread's special focus is all about Klinefelter's [XXY male] and both variants of XXY Female [SRY positive and SRY negative] - Let us begin using the five methods of sex determination. Do note we will not be going over X/XXY mosaic in this thread.

Klinefelter's is what happens when an extra X chromosome is placed into either ova or sperm before conception, this results in a typical as we know it XXY male. There are health concerns with klinefelter's but they appear to be minimal and passed off as something else.

Beginning with Karyotype:
XXY with an active and functioning SRY. The testis factor does indeed work and AMH activated meaning there is no real difference between this boy and another boy. These boys are born with a lower sperm count but with treatment young can be healthy.

External genitalia is clearly a penis, the size of the penis seems to vary though and can range from being a micropenis to the average recorded measurement for a male in adulthood. So yes, it's a dick.

Moving onwards to Gonads. There are very few reports where one or both testicles don't descend but there's no say whether this is another cause or related to more severe forms of KF. Still doesn't change they're for the most part functional, many even can produce functional sperm

Hormone Levels are but another case of variance. Males with this CCSD tend to have lower body hair then normal, altered fat distributions and these hormone levels can in fact impact their genitalia as well. That said the most severe variants of KF lead to a "null factor" here.

Lastly internal reproductive structures are male without a doubt. There are functional and working Wolffian ducts and the AMH[Anti-Mullerian Hormone] did its job. Entirely male.

In conclusion XXY Male Aka Klinefelter's is:
Karyotype: Male
Genitalia: Male
Gonads: Male
Hormone levels: Null or Male typical.
Internal Reproductive structures: Wolffian, male.

Someone with KF can obviously still be trans, we're discussing biological sex here not gender.

XXY Female [SRY-Negative] is a much more rare case that has no understanding how it occurs. Gonadal Dysgenesis tends to be connected to the degeneration of once present ovaries into streak gonads, but in a case like this that it's negated. This is absurdly rare, mind you.

Karyotype is that of a 47 XXY with deleted SRY. There is no AMH and there is no SRY gene to boot up the process connected to the other genes to push one down the male developmental path. Female.

Genitalia is a rather average in classification clitoris and a vagina that is not blind, meaning it leads to a cervix. The vagina appears to work as intended and these females have the sensory nerves and everything seemingly functional. Female.

Gonads is an interesting spectacle. Ovaries, completely functional ovaries. This particular condition is always female in this category.

Hormone levels are that of a typical female, down to the cycling of hormones and everything. Female.

Lastly internal reproductive structures show these individuals are capable of pregnancy and gestation naturally without IVF. No Wolffian structures and a fully working uterus and Mullerian ducts. Female.

Conclusion:
47 XXY - SRY Negative - Female.
Genitalia - Vagina, clitoris : Female
Gonads - Functional Ovaries : Female
Hormone Profile - Female typical
Internal Reproductive Structures - Mullerian, Uterus present - Female.

A female, arguably debatable if intersex.

XXY Female, with SRY or rather.. XXY AIS.
Much like AIS, this case is very tricky to navigate and all it depends on is one factor going one way to change this to a more standard KF diagnosis. These cases are very interesting because literally ANY of the factors can go a way.

Karyotype is 47 XXY, the SRY can either be working or be deleted similar to Swyer Syndrome like our other case. In cases of the SRY being there it seems to be determinant on whether certain other factors are in play. Arguably speaking? This karyotype is male, unless SRY is broken

Genitalia on case reports appears to be very female typical, a clitoris and a vagina that appears to be functional but where it gets interesting is that the vagina can be blind or lead to a cervix, but just because there is a cervix does not guarantee a uterus.

Gonads is where this case gets super interesting, like our other example the gonads can actually be ovaries in these cases but they can also be streak gonads OR internal testicles! The majority of reported cases were internal testicles, which seemed to be dysfunctional like AIS.

Hormone levels continues to be interesting, if the SRY isn't present it appears these cases are female typical but even if it is present it seems these cases have a mutation that occurs in one of the X chromosome that leads to gestation like AIS occurring leading to female levels

Internal reproductive structures seems to be another case of variance, it can either be a case similar to AIS where no mullerian or wolffian structures exist, or there are mullerian structures. This seems to very much depend on what happens with the SRY in these cases.

Conclusion more indepth, cause this case is complicated!

Karyotype can either be:
47 XXY SRY Positive, which is male.
47 XXY SRY Damaged, which is either male or female depending on other factors.
47 XXY SRY Deleted, which is female

External genitalia in these cases has always been observed and reported to be female-typical, a clitoris and a vagina so these are always female.

External Genitalia : Vagina, clitoris - Female.

Gonads is yet another case of multiple scenarios.
Internal Testicles that are feminized and dysfunctional: Null
Streak Gonads: Null
or Ovaries: Female.

Hormone levels, in terms of sex hormones it seems the result is one of two options, or technically three options.

Due to functional ovaries, the levels are female typical.
Due to dysfunctional internal testicles with the process of gestation: Female
Streak Gonads: Null

Lastly Internal Reproductive structures tend to be another variant case.

Most reported cases tend to be a case of neither mullerian nor wolffian being present, so this would be a null.

Few cases, particularly altered SRY reported Mullerian structures, or at least tissue.

All in all, these cases typically line up as
Karyotype: Male, or Female.
Genitalia is always female.
Gonads are either Null, or female
Hormone levels are either null or female.
and internal reproductive structures are either null, or female.

Even in the most severe case: Female.

This was actually a really fun thread to write, I enjoyed brushing myself up on the few recorded cases of XXY female. I actually didn't know about the similarities regarding a mutated X chromosome that caused androgen insensitivity myself!

If you made it to the end of the thread, you probably noticed I used the wrong term in two tweets. You'd be correct, I meant to use aromatase and not gestation. The only correct use of gestation is in the first XXY female variant.