Fifth day of intersex: Diagnosing intersex

On the Fifth Day of Intersex we draw your attention to intersex and one way a person might come to be intersex.

What is intersex?

Intersex people are people who, as individuals, have congenital genetic, hormonal and physical features that may be thought to be typical of both male and female at once. That is, we may be thought of as being male with female features, female with male features, or indeed we may have no clearly defined sexual features at all.

What are intersex chromosomal variations?

There are many ways to be intersex. Chromosomal variations are one.

Many people think that X and Y chromosomes are the sole determinants of sex. Consequently anyone who has a Y chromosome must in fact be male and the lack of a Y chromosome must therefore make one female.

The need to find a single absolute determinant of sex is driven by two human behaviours. The first is a need for absolute answers, black-and-white answers without subtle, hard-to-understand nuances. The second is the need for answers to life’s puzzles even when we have insufficient knowledge to give any.

The sex binary of male and female is currently society’s unsubtle, black-and-white answer to the puzzle of the differences between the sexes, all the variations in sex itself.

Recent research has shown that sex is, in fact, determined by the interaction of many genes not all of which reside on the so called “sex” chromosomes X and Y. It is more accurate to see the X and Y chromosomes as windows through which many genes express themselves in determining the make-up of our sex. It is also useful to see our sex make-up as existing on a continuum where no one of us is absolutely male or female. Rather, most people have attributes that see them clustered more towards the male or female ends of the spectrum with many possible variations in between.

Sex anatomy is a cloud of possibilities and most of those are known to exist in every part of the animal kingdom, us included.

What is XXY?

XXY is one such chromosomal variation. There are a wide variety of possible duplications and deletions of X and Y chromosomes – XXY/XY mosaicism, XXXY, XXX and many more – and there is even XO where a person has only one of the possible two or more chromosomes. Some combinations cannot sustain life – a single Y chromosome is one of these.

Those chromosomal differences are given a variety of names generally reflecting the surname of the first person to describe them. So XXY is commonly thought of as being Klinefelter’s syndrome. To think that every person with XXY, or a variation of chromosomes where there is a multiplicity of X combined with a Y, has Klinefelter’s syndrome is incorrect.

It is also incorrect to think of every person who is XXY as somehow being male.

In describing the people he was studying, Klinefelter was unaware that they had XXY chromosomes. Instead he thought that some mystical hormone was responsible for their differences. When he did become aware that chromosomal variations were present in the individuals he studied he did not change his diagnostic criteria. Not all people who have XXY chromosome fit Klinefelter’s diagnostic criteria and so not all XXY people are correctly classified as having Klinefelter’s.

Likewise no one who has XXY/XY mosaic or other multiplicities of X and Y chromosomes has Klinefelter’s as those variations were never considered by Klinefelter. XXY, not unlike the word “hermaphrodite”, is a label, a convenient shorthand for incompletely-informed medical practitioners and journalists.

Thus, all people with Klinefelter’s diagnosis have XXY chromosomes but not all XXY people have Klinefelter’s syndrome.

Are all XXY people really male?

The idea that all people with XXY chromosomes are male is apparently bolstered by what experts perceive about their external appearance. Despite XXY people’s outward physical appearance often being unquestioningly ambiguous, the “experts” treat them in the same way as they treat all intersex people – they fish for essential signs.

The “experts” do this in the face of substantial evidence from the diagnosed people themselves that they have got it wrong. They take the slightest indications from the appearance of those they inspect, collect them together into a ready-prepared set of expectations and then present an outcome that bolsters rather than challenges social norms.

Recent research and theory posits that when a person has variations like XXY it is impossible to classify them as simply male or female. Clearly this situation is a difficult, nuanced one for people who see human existence in the simple binary terms of male and female.

For XXY people themselves, if social pressures are removed, their own knowledge of their sex is far more certain and understandable than the one that medicine and society foist upon them. Though society struggles with the notion that there is no clear way of defining how XXY should be regarded in terms of the sex binary, XXY people themselves are more than able to cope if listened to.

There are simply no reasons to assume that all XXY people are male and likewise no reason to suppose they are all female. XXY people, like all humans, have a considerable range of physical variations. Some may be seen as male, some as female and some as neither. Best to ask if certainty is what you demand.

Likewise some XXY people are intersex and some are not. To force an XXY person into the intersex box is no different than forcing them into the male or female boxes. It is no different to forcing a non-consenting child into a male or female box.

Only XXY people have the right to declare their sex and their sex role, their intersex or not, only they and they alone.

Every time society and medicine desperately push a sex onto those of uncertain sex as a way of maintaining the social fiction of the sex binary, they take away the rights to psychological and anatomical autonomy of those who are physically non-compliant.

What is XXY really?

XXY is one of the infinite ways of being human, one of the many delightful variations that make us all unique and interesting.

XXY is also a way of discovering that you do not enjoy the same rights as everyone else because of common social hang-ups about sex and how they qualify us to be granted fundamental human rights.

Or not.

Gina Wilson
President, Organisation Intersex International Australia Limited (OII Australia)



Such differences of opinions as to what constitutes XXY appear to be fairly rampant amongst the medical fraternity, an example being recent blood tests from my GP whereupon he describes the anomaly as ‘Klinefelters Syndrome/Disease’ compare this to my treating endocrinologist who referred to it as simply ‘XXY’ and noted my gender as female.


A good call for understanding – but some clarification needed. Klinefelter syndrome describes a set of differences described by Dr Klinefelter and understood afterwards to be an expression of XXY sex chromosomes. Kleinfelter did not have the technical resources, or even a theoretical motivation to test his XXY patients for mosacism (having XXY in some cells and a different sex chromosome makeup in others). Newer research indicates that substantial proportion (in some studies a majority) of people who with a basic Kareotype test are revealed as XXY, on closer inspection (multi-site high-res kareotype testing) have mosaicism. This is new information that adds to our understanding of XXY and the Klinefelter cluster of differences (aka syndrome) – but this new information doesn’t stop the people who we now know to be Mosaic from fitting this profile (Klinefelter syndrome). It is true not all XXY people have Klinefelter Syndrome, but it is equally true that not all Klinefelter people have the exact same Kareotype (ie XXY mosaics are often Klinefelter) . With what we now know about sex Chromosome variations, a large portion of people who are simply classified XXY, and have Klinefelter differences, would with the appropriate testing be revealed as Mosaic. Dr Klinefelter’s original sample most probably included mosaicism, but the type of tests done could not, and were not intended to test this. It is true that other X/Y variations where XXY is not the majority Kareotype are not generally considered Klinefelters. Hope this clarifies things.

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