Biology of DSDs: Introduction

Description

Biology defines intersex. For this multi-part series, we'll be exploring the biology of eight intersex/DSD conditions: how each develops in the womb, how it may be diagnosed, and how it may impact the individuals who experience it.

If you want to help improve medical research and psychological support for individuals with these conditions, you can donate to DSD Families https://dsdfamilies.org/charity.

Sources

[1] Wilson, G. (2013). Third sex redux. Intersex Human Rights Australia.

[2] Witchel, S. (2017). Disorders of sex development. Best Practice and Research in Clinical Obstetrics and Gynaecology, 48, 90-102.

[3] DSDFamilies. (2020). Brief overview of differences in sex development. dsdfamilies.org.

[4] DSDFamilies. (2019). The Story of Sex Development. dsdfamilies.org.

[5] Sex. (n.d.) Merriam-Webster; Lehtonen, J., Parker, G. (2014). Gamete competition, gamete limitation, and the evolution of two sexes. Molecular Human Reproduction, 20(12); Cox, P., Togashi, T. (2011). The Evolution of Anisogamy, A Fundamental Phenomenon Underlying Sexual Selection. New York Cambridge University Press. 17.

[6] IHRA. (2014). Welcome! Intersex Human Rights Australia.

[7] Sax, L. (2002). How common is intersex? A response to Anne Fausto-Sterling. Journal of Sex Research.

[8] Vilain, E. (2016). Ovotesticular disorder of sex development. Rare Diseases.

[9] ClareCAIS. (2020). Caught in the middle. Differently Normal.

[10] Intersexfacts. (2020). Getting to grips with our sex is complicated. Twitter.

[11] Graham, C. (2019). Statistics and Semantics, Is Intersex As Common as Redheads. MRKHVoice.

[12] Lundberg, T., et al. (2017). Making sense of Intersex and DSD how laypeople understand and use terminology.

Transcript

Biology defines intersex, not identity. As Intersex Human Rights Australia explains, "Even though some intersex people define their identity as intersex, this is a political statement, and not necessarily anything about their gender or preference for sex classification. Identity is not what defines intersex: intersex is contingent on innate physical bodily characteristics."

The term intersex is often used in conversations about identity, but not many understand the biology. For this multi-part series, we'll be exploring the biology of eight intersex conditions: how each develops in the womb, how it may be diagnosed, and how it may impact the individuals who experience it.

Let's begin with terminology. There are a few ways to describe intersex conditions. You might see DSD: disorders of sex development or differences in sex development. Or you might see VSC: variations in sex characteristics. Intersex, DSD, and VSC are all commonly used as synonyms. We'll be using intersex and DSD interchangeably.

Next, what is intersex? Contrary to popular culture, intersex is not an amorphous mix of sex characteristics, or a third sex category, nor does the term describe hermaphrodites, which are organisms who have both sets of functioning reproductive anatomy. Rather, intersex (or Differences in Sex Development) is an umbrella term for separate congenital medical conditions of the reproductive system which affect males and females. Thus, like any other medical condition, there are males who have intersex conditions and females who have intersex conditions. Each intersex condition is unique, and thus, requires case-specific medical treatment. Despite this uniqueness, what intersex individuals share in common is that their innate sex characteristics differ from medical norms.

Individuals with DSDs may have rare chromosomal variations such as X (instead of XX), or XXY (instead of XY); they may have rare variations in genital morphology (such as Congenital Adrenal Hyperplasia in XX females, where an over-exposure to androgens causes virilization, or masculinization, of the genitals; they may have differences in hormone production (such as Complete Androgen Insensitivity Syndrome, where XY fetuses lack functioning androgen receptors, and develop a female phenotype); and they may have extremely rare differences in gonadal tissue (such as Ovotesticular Disorder, where complex genetic and hormonal anomalies produce a mix of ovarian and testicular tissue.) Because each condition is so unique, their biology must be treated case-by-case.

The rate of intersex conditions varies from 0.02% at birth to 1.7% throughout postnatal development. The exact rate depends upon how many conditions are included. For example, 47,XXY DSD (Klinefelter syndrome) is observed in only 0.1% of births, while late onset congenital adrenal hyperplasia (LOCAH) occurs at a rate of 1.5%. And some DSDs make up some of the rarest medical conditions on the planet; such as Ovotesticular Disorder, which has only had around 500 cases reported in the medical literature. Therefore, when it comes to medical treatment, what is most important is not the total number of cases, but rather an understanding of how each unique condition affects the individuals who experience it--on a biological, psychological, and social level.

When it comes to advocating for intersex, many believe that intersex individuals wish for the creation of a third sex category, but this is not a primary advocacy focus for intersex organizations. As IHRA notes, "Rather than define a catch-all 'other' category, we would prefer to minimize our participation in gender constructs; we do not wish for the creation of an equally confining third box." Because most intersex conditions are sex-specific and unique, a third sex category known as 'intersex' is not helpful nor desired.

In fact, the creation of more categories for people's bodies may lead to an increase in "intersex genital mutilation," or IGM, cosmetic surgeries conducted on an infant to make his or her body appear more typically male or female. Intersex individuals oppose IGM as a violation of their bodily autonomy and human rights. Because of this, parents must be able to accept that while their child may have a different body, this does not mean they need to be 'fixed.' There is nothing wrong with variation of body types.

While IGM is a violation of human rights, it should not be confused with necessary medical intervention. There are instances which require early medical help to prevent fatality of the child, such as the salt-wasting variety of Congenital Adrenal Hyperplasia. The important distinction between unnecessary and necessary medical surgeries is critical for parents of babies born with DSDs to understand. As a woman with CAIS writes, "Any medical or surgical intervention offered should have robust evidence and consider the long-term risks and complications. As with all types of surgery, this should be considered only when there is clinical need. Do no harm should be prioritized for any intervention" @clareCAIS).

Individuals born with differences in sex development are regular people each with their own unique perspectives, beliefs, and values. They deserve accurate medical information and patient-centered treatment which is focused on the needs of the individual. Because there are so many unique conditions, the reality of every individual with a DSD is different, and such diverse biology should not be conflated under a single umbrella.

With a basic understanding of the biology, and an understanding of how these conditions often affect the individuals who experience them, we can dispel myths, cultivate empathy for those living with a DSD, and develop a compassionate, scientifically-informed perspective on what it means to have a difference in sex development.

As another intersex woman notes, "Understanding a DSD can be complicated as can getting to grips with our sex. This is not because we are 'not male or female,' but because the journey of how we got there, our development, was a little bit different to most other people" ( @intersexfacts).

END

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