Understanding Intersex Biology: A Scientific Overview
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Chapter 1: The Scientific Landscape of Intersex
In recent discussions about intersex individuals, it is essential to delve into the biological aspects rather than just the social context. This piece aims to shed light on the scientific understanding of intersexuality, presenting ten distinct ways in which biological sex can manifest diversely.
To begin with, defining intersexuality can be challenging due to varying interpretations. The Oxford Dictionary simplistically states that 'intersex' refers to 'having characteristics of both sexes' (2007, p.1415). However, this definition fails to capture the complexity of the topic, particularly as the binary model of sex is increasingly scrutinized.
The legendary figure of Hermaphroditus—depicted as a deity possessing both male and female genitalia—serves as a reminder that such an individual does not exist in reality. Instead, variations in sexual characteristics are more prevalent than many might think, with approximately one in fifty people exhibiting some form of intersexuality.
In defining intersexuality, it may be more effective to describe what it is not. An intersex individual typically presents a variation from the conventional male or female characteristics. These variations can include differences in chromosomes, genital structures, hormone levels, or the atypical presence of internal testes in those assumed to be female and internal ovaries in those assumed to be male.
While the reasons for intersexuality remain unclear, several theories have emerged. These range from random genetic variations to atypical exposure to sex hormones in utero, as well as unexplained chromosomal anomalies.
According to interACT, a nonprofit organization that advocates for intersex youth, over thirty medical terms exist to describe specific intersex traits, indicating that the topic is far more nuanced than simply categorizing individuals as male, female, or intersex.
In the United States, alarming statistics indicate that five infants undergo non-essential surgeries aimed at 'correcting' their intersex traits daily (Thea Hillman, 2008). It is vital to acknowledge that the majority of intersex characteristics are not life-threatening or physically detrimental, although exceptions do exist, as I will discuss shortly.
I also wish to express my discomfort with the medical terminology often used to describe intersex individuals. Such language can feel reductive, reducing individuals to mere subjects of study rather than recognizing their personhood. This sentiment is similar to how society has moved away from using medical labels for those attracted to the same sex. I hope that one day, intersex discussions will evolve in a similar manner.
XX and XY: The Typical Cisgender Framework
Typically, individuals with XX chromosomes are expected to develop female reproductive structures and are usually assigned female at birth. Conversely, those with XY chromosomes are anticipated to develop male reproductive organs and be assigned male at birth. During fetal development, two small organs called proto-gonads emerge, which usually develop into either testes or ovaries; however, this is not always the case. It’s essential to note that biological factors concerning intersexuality do not dictate an individual’s gender identity or sexual orientation.
Androgen Insensitivity Syndrome (AIS)
Individuals born with AIS possess XY chromosomes and testes as expected. However, they may be resistant to or unable to respond to androgens such as testosterone. This resistance can lead to the development of external genitalia that appears ambiguous or female.
AIS includes two subcategories: Complete Androgen Insensitivity Syndrome (CAIS) and Partial Androgen Insensitivity Syndrome (PAIS).
In cases of PAIS, the degree of insensitivity varies, leading to male genitalia that may be smaller than average. Often, individuals are unaware of this condition until they face infertility issues as adults. Consequently, visibility may influence perceptions of intersexuality, causing some to overlook PAIS as a form of intersex.
Conversely, CAIS results in individuals with XY chromosomes developing external female genitalia despite having internal testes. Due to the presence of these testes, they lack a uterus and fallopian tubes, and medical professionals typically assign them female at birth, anticipating breast development during puberty.
Medical recommendations sometimes suggest gonadectomies (removal of the testes) for individuals with AIS, citing a low cancer risk associated with the testes.
XY Complete Gonadal Dysgenesis
XY complete gonadal dysgenesis, also known as Swyer Syndrome, describes a condition where individuals with XY chromosomes do not develop testes, resulting in the formation of a vulva and underdeveloped uterus. The tissue that typically forms testes becomes 'streaks,' which can carry a 30% risk of cancer, often necessitating removal due to lack of function.
Children with this condition typically do not undergo normal puberty without hormone therapy and are usually assigned female at birth.
XY Partial Gonadal Dysgenesis
Similar to Swyer Syndrome, this condition involves the partial development of testes. Over time, these testes may shrink or disappear, and the appearance of external genitalia can vary widely. The risk of cancer in such cases ranges from 20-30%.
Ovotesticular DSD
In certain instances, the proto-gonads may develop into an ovotestis, containing both ovarian and testicular cells. Most individuals with this condition possess one ovotestis alongside either an ovary or testis. Due to varying external genitalia presentations, diagnosing children with ovotestes can be challenging.
XXY Syndrome
XXY Syndrome, or Klinefelter Syndrome, occurs when an individual has an extra X chromosome. Typically presenting as male, individuals may experience less body and facial hair, reduced muscle mass, and lower testosterone levels. While they often produce minimal sperm, hormone therapy can often address this issue.
X0 Turner Syndrome (TS)
Individuals with Turner Syndrome possess one complete X chromosome, while their second X chromosome is either absent or underdeveloped. This condition affects approximately 0.05% of births, leading to underdeveloped ovaries, resulting in 'streaks' instead of functioning ovaries. As a result, these individuals may not experience puberty or may undergo atypical developmental changes, often resulting in shorter stature.
5-Alpha Reductase-3 Deficiency and 17 Beta-Hydroxysteroid Dehydrogenase-3 Deficiency
These conditions arise when babies with XY chromosomes experience mutations affecting hormone levels in their testes. While they possess internal testes, the production of weaker androgens can lead to the development of a vulva. Such individuals are often assigned female at birth and may not realize their intersex status until puberty, when they experience secondary male characteristics. Medical intervention is typically administered to suppress these changes.
Hypospadias and Epispadias
Hypospadias occurs when the urethra opens below its typical location on the penis, affecting approximately 0.3–0.8% of XY births. The urethral opening can be positioned anywhere from just below the tip of the penis to near the rectum, potentially resulting in a bent penis.
Epispadias is a less common condition, characterized by the urethra opening on the upper side of the penis or in the middle of the clitoris, and may require surgical correction, often performed before the child turns one.
XX Salt-Wasting Congenital Adrenal Hyperplasia (SWCAH)
CAH refers to a condition where babies with XX chromosomes possess a uterus and ovaries, yet their external genitalia may appear atypical. SWCAH involves genetic mutations in adrenal enzymes that regulate hormone production. This can lead to excessive androgen production, causing significant health issues, such as dehydration and blood pressure drops, which can be life-threatening.
Intersexuality encompasses a wide array of conditions, and this overview has barely scratched the surface. For those interested in understanding how societal perspectives on intersexuality have evolved, further reading is encouraged.
The first video titled "What Does Intersex Mean? | InQueery | them" provides insight into the definition and understanding of intersex.
The second video, "Living an Intersex Life," shares personal experiences and challenges faced by intersex individuals.