When examined at the cell level, people are either male (an X chromosome and a Y chromosome), female (an X and an X)
or in some cases show signs of mixed sex.
A small subset of people are born genetically male but in the womb "maleness" development is shut down and these people grow up to look like and to subjectively feel like females. In their minds, they are women. Their sexual organs are usually insufficient for natural childbirth.
One study reported, "Despite the fact that children with partial androgen effects reared as girls showed increased 'boyish' behaviors, they did not show increased signs of gender identity confusion or instability on a group level."
It has also been reported that XY women, though feminine, tend to problem-solve like a male.
Then there are those XY people who regard themselves as male but who display signs of dysfunctional testosterone take-up before birth. Such androgen effects can range from rather mild to severe. Yet, in their minds they are male and it is often the case that these androgen-deficient males are never diagnosed with this disorder.
So the social point of contention is: Can XY persons who are born without androgen deficiency be classed as female based solely on psychological factors? Suppose an XY person receives estrogen therapy, which suppresses testosterone and promotes female traits? Is the transition sufficient for general acceptance by men and women that the person is "truly female"? Such persons don't seem to lose their masculine traits altogether. Deep voices and superior athletic strength are often found among such persons.
Related questions:
If an XX person believes she/he is male, or ought to be, is "belief" a sufficient criterion? And what of the XX person who receives testosterone therapy? That therapy is a treatment that induces typically masculine physical traits while suppressing typically feminine ones. We know that XY women with androgen deficiency are generally accepted as women by both women and men, but the same cannot be generally said of XX persons with testosterone-induced traits.
From various reputable sources:
A small subset of people are born genetically male but in the womb "maleness" development is shut down and these people grow up to look like and to subjectively feel like females. In their minds, they are women. Their sexual organs are usually insufficient for natural childbirth.
One study reported, "Despite the fact that children with partial androgen effects reared as girls showed increased 'boyish' behaviors, they did not show increased signs of gender identity confusion or instability on a group level."
It has also been reported that XY women, though feminine, tend to problem-solve like a male.
Then there are those XY people who regard themselves as male but who display signs of dysfunctional testosterone take-up before birth. Such androgen effects can range from rather mild to severe. Yet, in their minds they are male and it is often the case that these androgen-deficient males are never diagnosed with this disorder.
So the social point of contention is: Can XY persons who are born without androgen deficiency be classed as female based solely on psychological factors? Suppose an XY person receives estrogen therapy, which suppresses testosterone and promotes female traits? Is the transition sufficient for general acceptance by men and women that the person is "truly female"? Such persons don't seem to lose their masculine traits altogether. Deep voices and superior athletic strength are often found among such persons.
Related questions:
If an XX person believes she/he is male, or ought to be, is "belief" a sufficient criterion? And what of the XX person who receives testosterone therapy? That therapy is a treatment that induces typically masculine physical traits while suppressing typically feminine ones. We know that XY women with androgen deficiency are generally accepted as women by both women and men, but the same cannot be generally said of XX persons with testosterone-induced traits.
From various reputable sources:
https://pubmed.ncbi.nlm.nih.gov/17306800/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4350266/
https://medlineplus.gov/genetics/condition/androgen-insensitivity-syndrome/#resources
https://novonordiskfonden.dk/en/news/more-women-than-expected-are-genetically-men/
https://medlineplus.gov/genetics/condition/klinefelter-syndrome/
https://www.medicalnewstoday.com/articles/ftm-testosterone#why-a-person-has-it
Androgen insensitivity syndrome is a condition that affects sexual development before birth and during puberty. People with this condition are genetically male, with one X chromosome and one Y chromosome in each cell. Because their bodies are unable to respond to certain male sex hormones (called androgens), they may have mostly female external sex characteristics or signs of both male and female sexual development.
Complete androgen insensitivity syndrome occurs when the body cannot use androgens at all. People with this form of the condition have the external sex characteristics of females, but do not have a uterus and therefore do not menstruate and are unable to conceive a child (infertile). They are typically raised as females and have a female gender identity. Affected individuals have male internal sex organs (testes) that are undescended, which means they are abnormally located in the pelvis or abdomen. Undescended testes have a small chance of becoming cancerous later in life if they are not surgically removed. People with complete androgen insensitivity syndrome also have sparse or absent hair in the pubic area and under the arms.
The partial and mild forms of androgen insensitivity syndrome result when the body's tissues are partially sensitive to the effects of androgens. People with partial androgen insensitivity (also called Reifenstein syndrome) can have genitalia that look typically female, genitalia that have both male and female characteristics, or genitalia that look typically male. They may be raised as males or as females and may have a male or a female gender identity. People with mild androgen insensitivity are born with male sex characteristics, but they are often infertile and tend to experience breast enlargement at puberty.
Frequency
Complete androgen insensitivity syndrome affects 2 to 5 per 100,000 people who are genetically male. Partial androgen insensitivity is thought to be at least as common as complete androgen insensitivity. Mild androgen insensitivity is much less common.
Causes
Mutations in the AR gene cause androgen insensitivity syndrome. This gene provides instructions for making a protein called an androgen receptor. Androgen receptors allow cells to respond to androgens, which are hormones (such as testosterone) that direct male sexual development. Androgens and androgen receptors also have other important functions in both males and females, such as regulating hair growth and sex drive. Mutations in the AR gene prevent androgen receptors from working properly, which makes cells less responsive to androgens or prevents cells from using these hormones at all. Depending on the level of androgen insensitivity, an affected person's sex characteristics can vary from mostly female to mostly male.
Klinefelter syndrome (XXY)
Some boys are born with a girl's genes plus the male y gene: XXY. This chromosome structure can result in Klinefelter syndrome, which can affect physical and intellectual development. Most commonly, affected individuals are taller than average, are unable to father biological children (infertile) and score below average on mental development tests. But signs and symptoms vary. In some cases, the features are so mild that the condition is not diagnosed until puberty or adulthood, and researchers believe that up to 75 percent of affected men and boys are never diagnosed.
Boys and men with Klinefelter syndrome typically have small testes that produce a reduced amount of testosterone (primary testicular insufficiency). Testosterone is the hormone that directs male sexual development before birth and during puberty. Without treatment, the shortage of testosterone can lead to delayed or incomplete puberty, breast enlargement (gynecomastia), decreased muscle mass, decreased bone density, and a reduced amount of facial and body hair. As a result of the small testes and decreased hormone production, affected males are infertile but may benefit from assisted reproductive technologies. Some affected individuals also have differences in their genitalia, including undescended testes (cryptorchidism), the opening of the urethra on the underside of the penis (hypospadias), or an unusually small penis (micropenis).
Other physical changes associated with Klinefelter syndrome are usually subtle. Older children and adults with the condition tend to be somewhat taller than their peers. Other differences can include abnormal fusion of certain bones in the forearm (radioulnar synostosis), curved pinky fingers (fifth finger clinodactyly) and flat feet (pes planus).
Children with Klinefelter syndrome may have low muscle tone (hypotonia) and problems with coordination that may delay the development of motor skills, such as sitting, standing, and walking. Affected boys often have learning disabilities, resulting in mild delays in speech and language development and problems with reading. Boys and men with Klinefelter syndrome tend to have better receptive language skills (the ability to understand speech) than expressive language skills (vocabulary and the production of speech) and may have difficulty communicating and expressing themselves.
Individuals with Klinefelter syndrome tend to have anxiety, depression, impaired social skills, behavioral problems such as emotional immaturity and impulsivity, attention-deficit/hyperactivity disorder (ADHD), and limited problem-solving skills (executive functioning). About 10 percent of boys and men with Klinefelter syndrome have autism spectrum disorder.
Nearly half of all men with Klinefelter syndrome develop metabolic syndrome, which is a group of conditions that include type 2 diabetes, high blood pressure (hypertension), increased belly fat, high levels of fats (lipids) such as cholesterol and triglycerides in the blood. Compared with unaffected men, adults with Klinefelter syndrome also have an increased risk of developing involuntary trembling (tremors), breast cancer (if gynecomastia develops), thinning and weakening of the bones (osteoporosis), and autoimmune disorders such as systemic lupus erythematosus and rheumatoid arthritis. (Autoimmune disorders are a large group of conditions that occur when the immune system attacks the body's own tissues and organs.)
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A few XXY cases with a female phenotype have been reported. These individuals have positive SRY (testis-determining factor). The genetic explanation of this phenomenon is unclear.
